G. Navarro and J. Tarhio. Boyer-Moore string matching over Ziv-Lempel compressed text. In 11th Annual Symposium on Combinatorial Pattern Matching (CPM'2000.  Home/Search   Document Details and Download   Summary   Related Articles   Check

.... without decoding it, which is often referred to as compressed pattern matching , has been studied extensively [4] 18] 43] Along these lines, string search in compressed text was developed for the compression paradigm of LZ78 [52] and its subsequent variant LZW [50] as described in [30] [44]. A more challenging problem is that of fully compressed pattern matching when both the pattern and text strings are compressed [21] 22] For the LZ78 LZW paradigm, compressed matching has been extended and generalized to that of approximate pattern matching ( nding all occurrences of a ....

Navarro, G., and M. Ranot. Boyer-Moore string matching over Ziv-Lempel compressed text, Proc. 11th Annual Symposium On Combinatorial Pattern Matching, LNCS 1848, 166-180 (2000).

....Super alphabet methods have appeared before, and the idea was mentioned already in [11, 5] In [2] the bmh algorithm [9] was modi ed to use a super alphabet. This e ectively reduced the probability of match of two random characters, thus yielding longer shifts. Similar methods were presented in [17, 16]. These techniques di er from the one taken here; we apply our method to a sux automaton [7] often called bdm, for backward dag matching) which is also able to skip characters of T , but we do not try to make the shifts larger, in fact the shifts are exactly the same as in the original method. ....

G. Navarro and J. Tarhio. Boyer-Moore string matching over ziv-lempel compressed text. In R. Giancarlo and D. Sanko, editors, Proceedings of the 11th Annual Symposium on Combinatorial Pattern Matching, number 1848 in Lecture Notes in Computer Science, pages 166-180, Montreal, Canada, 2000. SpringerVerlag, Berlin.

....on the bit parallelism for LZW is O(nm=w m r) where n is the text length and w is the length in bits of the machine word. If the pattern is short (m w) these algorithms are ecient in practice. A Boyer Moore type algorithm for a single pattern on Ziv Lempel compressed text is also developed [15]. 3 Preliminaries Let be a nite set of characters, called an alphabet. A nite sequence of characters is called a string. We denote the length of a string u by juj. The empty string is denoted by , that is, j j = 0. Let be the set of strings over , and let = nf g. Strings ....

G. Navarro and J. Tarhio. Boyer-Moore string matching over Ziv-Lempel compressed text. In Proc. 11th Ann. Symp. on Combinatorial Pattern Matching, volume 1848 of Lecture Notes in Computer Science, pages 166-180. Springer-Verlag, 2000.

.... without decoding it, which is often referred to as compressed pattern matching , has been studied extensively [3] 13] 34] Along these lines, string search in compressed text was developed for the compression paradigm of LZ78 [45] and its subsequent variant LZW [43] as described in [23] [35]. A more challenging problem is that of fully compressed pattern matching when both the pattern and text strings are compressed [16] 17] For the LZ78 LZW paradigm, compressed matching has been extended and generalized to that of approximate pattern matching ( nding all occurrences of a short ....

Navarro, G., and M. Ranot. Boyer-Moore string matching over Ziv-Lempel compressed text, Proc. 11th Annual Symposium On Combinatorial Pattern Matching, LNCS 1848, 166-180 (2000).

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G. Navarro and J. Tarhio. Boyer-Moore string matching over Ziv-Lempel compressed text. In Proc. 11th Annual Symp. on Combinatorial Pattern Matching (CPM 2000.

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G. Navarro and J. Tarhio. Boyer-Moore string matching over Ziv-Lempel compressed text. In Proc. 11th Annual Symposium on Combinatorial Pattern Matching (CPM 2000), LNCS 1848, pages 166--180, 2000.

....text. Compression schemes based on Hu man codes are not often used on natural language because of the poor compression ratios achieved. On the other hand, Ziv and Lempel algorithms obtain better compression ratios, but the search for a word on the compressed text is inecient. Empirical results [10] showed that searching on a Ziv Lempel compressed text can take half the time of decompressing that text and then searching it. However, the compressed search is twice as slow as just searching the uncompressed version of the text. In [12] Moura et al. present a compression scheme that uses a ....

G. Navarro and J. Tarhio. Boyer-moore string matching over ziv-lempel compressed text. In Proc. 11th Annual Symposium on Combinatorial Pattern Matching (CPM'2000), LNCS 1848, pages 166-180, 2000.

....competitive and convenient for search purposes. A similar result, restricted to the LZW format, was independently found and presented by Kida et al. 14] The same group generalized the existing algorithms and nicely uni ed the concepts in a general framework [12] Recently, Navarro and Tarhio [28] presented a new, faster, algorithm based on Boyer Moore. Approximate string matching on compressed text aims at nding the pattern where a limited number of di erences between the pattern and its occurrences are permitted. The problem, advocated in 1992 [2] was solved for Hu man coding of words ....

G. Navarro and J. Tarhio. Boyer-Moore string matching over Ziv-Lempel compressed text. In Proc. 11th Annual Symposium on Combinatorial Pattern Matching (CPM'2000.

....and extended patterns) and specialized it for the particular cases of LZ77, LZ78 and LZ Blocks, proposed there. A similar result, restricted to simple patterns and to the LZW format, was independently found and presented in [KTS 99] A Boyer Moore type algorithm for LZ78 LZW was presented in [NT00] which is currently the fastest in practice for moderately long patterns. An interesting abstraction of the existing algorithms over a general compression format called collage systems was presented in [KST 99] Approximate string matching on compressed text was advocated in [AB92] It has ....

G. Navarro and J. Tarhio. Boyer-Moore string matching over Ziv-Lempel compressed text. In Proc. CPM'2000, LNCS 1848, pages 166-180, 2000.

....searching of a set of pattern pieces plus local decompression and direct verification of candidate text areas. Apart from the existing algorithm for multipattern searching on compressed text [KTS 98] we propose a couple of new algorithms by adapting existing single pattern search algorithms [NT00, NR99, KTS 99] Our experimental results show that, for moderate error level k=m, the new algorithms are faster than the naive approach of uncompressing plus searching (up to 3 times faster for low enough error levels) For this moderate error level, the new algorithms are about 10 30 times ....

....Thus, the algorithm runs in O(m 2 n R) time using O(m 2 n) space. The details are involved and the reader interested in them is referred to the original paper [KTS 98] 4. 2 A Boyer Moore Technique An existing Boyer Moore technique to search a single pattern on compressed text [NT00] can be adapted to multipattern searching. The Boyer Moore technique [BM77] consists in aligning the pattern in a text window and comparing the window text characters with the corresponding pattern characters. If a mismatch occurs, then a safe shift is computed, which permits to slide the window ....

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G. Navarro and J. Tarhio. Boyer-Moore string matching over Ziv-Lempel compressed text. In Proc. CPM'2000, LNCS 1848, pages 166--180, 2000.

....competitive and convenient for search purposes. A similar result, restricted to the LZW format, was independently found and presented by Kida et al. 14] The same group generalized the existing algorithms and nicely unified the concepts in a general framework [12] Recently, Navarro and Tarhio [25] presented a new, faster, algorithm based on Boyer Moore. Approximate string matching on compressed text aims at finding the pattern where a limited number of differences between the pattern and its occurrences are permitted. The problem, advocated in 1992 [2] had been solved for Huffman coding ....

G. Navarro and J. Tarhio. Boyer-Moore string matching over Ziv-Lempel compressed text. In Proc. CPM'2000, LNCS 1848, pages 166--180, 2000.

....compressed texts (simple and extended patterns) and specialized it for the particular cases of LZ77, LZ78 and a new variant proposed which was competitive and convenient for search purposes. A similar result, restricted to the LZW format, was independently found and presented in [12] In [17] a new, faster, algorithm was presented based on Boyer Moore. The aim of this paper is to present a general solution to the approximate string matching problem on compressed text in the LZ78 and LZW formats. 3 Approximate String Matching by Dynamic Programming We introduce some notation for ....

G. Navarro and J. Tarhio. Boyer-Moore string matching over Ziv-Lempel compressed text. In Proc. CPM'2000, LNCS, 2000. In this same volume.

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G. Navarro and J. Tarhio. Boyer-Moore string matching over Ziv-Lempel compressed text. In 11th Annual Symposium on Combinatorial Pattern Matching (CPM'2000.

No context found.

G. Navarro and J. Tarhio. Boyer-Moore string matching over Ziv-Lempel compressed text. In Proc. 11th Ann. Symp. on Combinatorial Pattern Matching,vol- ume 1848 of Lecture Notes in Computer Science, pages 166--180. Springer-Verlag, 2000.

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