@inproceedings{583f66e8d5434c26a1bfee6b8cbc1a14,

title = "Alignment distance of regular tree languages",

abstract = "We consider the tree alignment distance problem between a tree and a regular tree language. The tree alignment distance is an alternative of the tree edit-distance, in which we construct an optimal alignment between two trees and compute its cost instead of directly computing the minimum cost of tree edits. The alignment distance is crucial for understanding the structural similarity between trees. We, in particular, consider the following problem: given a tree t and a tree automaton recognizing a regular tree language L, find the most similar tree from L with respect to t under the tree alignment metric. Regular tree languages are commonly used in practice such as XML schema or bioinformatics. We propose an O(mn) time algorithm for computing the (ordered) alignment distance between t and L when the maximum degree of t and trees in L is bounded by a constant, and O(mn2) time algorithm when the maximum degree of trees in L is not bounded, where m is the size of t and n is the size of finite tree automaton for L. We also study the case where a tree is not necessarily ordered, and show that the time complexity remains O(mn) if the maximum degree is bounded and MAX SNP-hard otherwise.",

keywords = "Alignment edit-distance, Regular tree languages, Tree alignment, Tree automata",

author = "Han, {Yo Sub} and Ko, {Sang Ki}",

note = "Publisher Copyright: {\textcopyright} Springer International Publishing AG 2017.; 22nd International Conference on Implementation and Application of Automata, CIAA 2017 ; Conference date: 27-06-2017 Through 30-06-2017",

year = "2017",

doi = "10.1007/978-3-319-60134-2_11",

language = "English",

isbn = "9783319601335",

series = "Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)",

publisher = "Springer Verlag",

pages = "126--137",

editor = "Arnaud Carayol and Cyril Nicaud",

booktitle = "Implementation and Application of Automata - 22nd International Conference, CIAA 2017, Proceedings",

address = "Germany",

}