The Induced Subtree Isomorphism problem takes as input a graph G and a tree T , and the task is to decide whether G has an induced subgraph that is isomorphic to T . This problem is known to be NP-complete on bipartite graphs, but it can be solved in polynomial time when G is a forest. We show that Induced Subtree Isomorphism can be solved in polynomial time when G is an interval graph. In cont...

This paper presents the experimental study conducted over the INEX 2007 Document Mining Challenge corpus employing a frequent subtree-based incremental clustering approach. Using the structural information of the XML documents, the closed frequent subtrees are generated. A matrix is then developed representing the closed frequent subtree distribution in documents. This matrix is used to progres...

Numerous researchers have proposed to use relational databases to store and query XML documents. In these systems, the elements selected by an XML query are returned to an application either by select mode or by reconstruct mode. For the reconstruct mode, the XML subtrees that are rooted at the selected elements need to be extracted and reconstructed from the relational storage of XML documents...

The Maximum Agreement Subtree Problem was posed by Finden and Gordon in 1985, and is as follows: given a set S={s,, sz,..., s,,} and two trees P and Q leaf-labelled by the elements of S, find a maximum cardinality subset S, of S such that PI S, = Q IS,. This problem arises in evolutionary tree construction, where different methods or data yield (possibly) different trees for the same species on...

With the exponential increase in the amount and size of XML data on the Internet, XML subtree matching has become important for many application areas such as change detection, keyword retrieval and knowledge discoveries over XML documents. In our previous work, we have proposed leaf-clustering based approximate XML subtree matching methods using syntax information of both the clustered leaf no...

The maximum common embedded subtree problem, which generalizes the minor containment problem on trees, is reduced for ordered trees to a variant of the longest common subsequence problem. While the maximum common embedded subtree problem is known to be APX-hard for unordered trees, an exact solution for ordered trees can be found in polynomial time. In this paper, the longest common balanced se...

In this paper, we present a polynomial-time algorithm for TPQ (tree pattern queries) minimization without XML constraints involved. The main idea of the algorithm is a dynamic programming strategy to find all the matching subtrees within a TPQ. A matching subtree implies a redundancy and should be removed in such a way that the semantics of the original TPQ is not damaged. Our algorithm consist...

In this paper, we define the Maximum-Mean Subtree problem on trees, an equivalent reformulation of the Fractional Prize-Collecting Steiner Tree Problem on Trees. We describe an algorithm that solves the Maximum-Mean Subtree problem, and prove that our algorithm runs in O(n) time in the worst case, improving a previous O(n log n) algorithm. 1 The Maximum-Mean Subtree Problem Given a rooted tree ...

In this paper, we give a (polynomial-time) 3-approximation algorithm for the rooted subtree prune and regraft distance between two phylogenetic trees. This problem is known to be NP-complete and the best previously known approximation algorithm is a 5-approximation. We also give a faster fixed-parameter algorithm for the rooted subtree prune and regraft distance than was previously known.