Masahiro Hirao

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Finding a pattern which separates two sets is a critical task in discovery. Given two sets of strings, consider the problem to find a subsequence that is common to one set but never appears in the other set. The problem is known to be NP-complete. Episode pattern is a generalized concept of subsequence pattern where the length of substring containing the(More)
Given two sets of strings, consider the problem to find a subsequence that is common to one set but never appears in the other set. The problem is known to be NP-complete. We generalize the problem to an optimization problem, and give a practical algorithm to solve it exactly. Our algorithm uses pruning heuristic and subsequence automata, and can find the(More)
Episode pattern is a generalized concept of subsequence pattern where the length of substring containing the subsequence is bounded. Given two sets of strings, consider an optimization problem to find a best episode pattern that is common to one set but not common in the other set. The problem is known to be NP-hard. We give a practical algorithm to solve(More)
We consider a fully compressed pattern matching problem , where both text T and pattern P are given by its succinct representation, in terms of straight-line programs and its variant. The length of the text T and pattern P may grow exponentially with respect to its description size n and m, respectively. The best known algorithm for the problem runs in O(n(More)
Sequitur due to Nevill-Manning and Witten. [19] is a powerful program to infer a phrase hierarchy from the input text, that also provides extremely effective compression of large quantities of semi-structured text [18]. In this paper, we address the problem of searching in Sequitur compressed text directly. We show a compressed pattern matching algorithm(More)
We address the problem of musical sequence comparison for melodic similarity. Starting with a very simple similarity measure, we improve it step-by-step to finally obtain an acceptable measure. While the measure is still simple and has only two tuning parameters, it is better than that proposed by Mongeau and Sankoff (1990) in the sense that it can(More)
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