|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Information Science and Technology / Faculty of Information Science and Technology >
Peer-reviewed Journal Articles, etc >
A Space-Saving Approximation Algorithm for Grammar-Based Compression
| Title: | A Space-Saving Approximation Algorithm for Grammar-Based Compression |
| Authors: | Sakamoto, Hiroshi Browse this author | | Maruyama, Shirou Browse this author | | Kida, Takuya Browse this author | | Shimozono, Shinichi Browse this author |
| Keywords: | Grammar-based compression | | Approximation algorithm | | Minimum CFG problem |
| Issue Date: | Feb-2009 |
| Publisher: | Institute of Electronics, Information and Communication Engineers |
| Journal Title: | IEICE Transactions on Information and Systems |
| Volume: | E92-D |
| Issue: | 2 |
| Start Page: | 158 |
| End Page: | 165 |
| Publisher DOI: | 10.1587/transinf.E92.D.158 |
| Abstract: | A space-efficient approximation algorithm for the grammar-based compression problem, which requests for a given string to find a smallest context-free grammar deriving the string, is presented. For the input length n and an optimum CFG size g, the algorithm consumes only O(g log g) space and O(n log*n) time to achieve O((log*n)log n) approximation ratio to the optimum compression, where log*n is the maximum number of logarithms satisfying log log…log n > 1. This ratio is thus regarded to almost O(log n), which is the currently best approximation ratio. While g depends on the string, it is known that g =Ω(log n) and $g=\Omega(\log n)$ and $g=O\left(\frac{n}{log_kn}\right)$ for strings from k-letter alphabet[12]. |
| Rights: | Copyright@2009 IEICE |
| Relation: | http://search.ieice.org/ |
| Type: | article |
| URI: | http://hdl.handle.net/2115/47139 |
| Appears in Collections: | 情報科学院・情報科学研究院 (Graduate School of Information Science and Technology / Faculty of Information Science and Technology) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
|
Submitter: 喜田 拓也
|
