Subtree matching is an important problem in Computer Science on which a number of tasks, such as mechanical theorem proving, term-rewriting, symbolic computation and nonprocedural programming languages are based on. A systematic approach to the construction of subtree pattern matchers by deterministic pushdown automata, which read subject trees in prefix and postfix notation, is presented. The ...

The tree-metric theorem provides a necessary and sufficient condition for a dissimilarity matrix to be a tree metric, and has served as the foundation for numerous distance-based reconstruction methods in phylogenetics. Our main result is an extension of the tree-metric theorem to more general dissimilarity maps. In particular, we show that a tree with n leaves is reconstructible from the weigh...

We propose the subtree ranking approach to parse forest reranking which is a generalization of current perceptron-based reranking methods. For the training of the reranker, we extract competing local subtrees, hence the training instances (candidate subtree sets) are very similar to those used during beamsearch parsing. This leads to better parameter optimization. Another chief advantage of the...

In this paper, we present an Expectation-Maximization learning algorithm (E.M.) for estimating parameters of partially-constrained Bayesian trees. The Bayesian trees considered here consist of an unconstrained subtree and a set of constrained subtrees. In this tree structure, constraints are imposed on some of the parameters of the parametrized conditional distributions, such that all condition...

In tree search, depth-first search (DFS) often uses ordering successor heuristics. If the heuristic makes a mistake ordering a bad successor (without goals in its subtree) before good ones (wi th goals in their subtrees), DFS has to unsuccessfully traverse the whole bad subtree before f inding a goal. To prevent this useless work, we present a new strategy called interleaved depthfirst search (...

Information extraction from HTML pages has been conventionally treated as plain text documents extended with HTML tags. However, the growing maturity and correct usage of HTML/XHTML formats open an opportunity to treat Web pages as trees, to mine the rich structural context in the trees and to learn accurate extraction rules. In this paper, we generalize the notion of delimiter developed for th...

In the paper, we present an approach to inferring 3D subtree structures from image pairs. The 3D structure is treated as a hidden Bayesian network, of which each node corresponds to an attributed skeleton point. The network structure is inferred in a bottom-up fashion. At the beginning, the root node of a subtree is manually specified in the images and then computed using stereo triangulation. ...