### Abstract

Lingua originale | English |
---|---|

pagine (da-a) | 315-328 |

Numero di pagine | 14 |

Rivista | RAIRO. INFORMATIQUE THEORIQUE ET APPLICATIONS |

Volume | 46 |

Stato di pubblicazione | Published - 2012 |

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### All Science Journal Classification (ASJC) codes

- Software
- Mathematics(all)
- Computer Science Applications

### Cita questo

**On the size of transducers for bidirectional decoding of prefix codes.** / Giambruno, Laura; Mantaci, Sabrina.

Risultato della ricerca: Article

*RAIRO. INFORMATIQUE THEORIQUE ET APPLICATIONS*, vol. 46, pagg. 315-328.

}

TY - JOUR

T1 - On the size of transducers for bidirectional decoding of prefix codes

AU - Giambruno, Laura

AU - Mantaci, Sabrina

PY - 2012

Y1 - 2012

N2 - In a previous paper [L. Giambruno and S. Mantaci, Theoret. Comput. Sci. 411 (2010) 1785–1792] a bideterministic transducer is defined for the bidirectional deciphering of words by the method introduced by Girod [IEEE Commun. Lett. 3 (1999) 245–247]. Such a method is defined using prefix codes. Moreover a coding method, inspired by the Girod’s one, is introduced, and a transducer that allows both right-to-left and left-to-right decoding by this method is defined. It is proved also that this transducer is minimal. Here we consider the number of states of such a transducer, related to some features of the considered prefix code X. We find some bounds of such a number of states in relation with different notions of “size” of X. In particular, we give an exact formula for the number of states of transducers associated to maximal prefix codes. We moreover consider two special cases of codes: maximal uniform codes and a class of codes, that we name string-codes. We show that they represent, for maximal codes, the extreme cases with regard to the number of states in terms of different sizes. Moreover we prove that prefix codes corresponding to isomorphic trees have transducers that are isomorphic as unlabeled graphs.

AB - In a previous paper [L. Giambruno and S. Mantaci, Theoret. Comput. Sci. 411 (2010) 1785–1792] a bideterministic transducer is defined for the bidirectional deciphering of words by the method introduced by Girod [IEEE Commun. Lett. 3 (1999) 245–247]. Such a method is defined using prefix codes. Moreover a coding method, inspired by the Girod’s one, is introduced, and a transducer that allows both right-to-left and left-to-right decoding by this method is defined. It is proved also that this transducer is minimal. Here we consider the number of states of such a transducer, related to some features of the considered prefix code X. We find some bounds of such a number of states in relation with different notions of “size” of X. In particular, we give an exact formula for the number of states of transducers associated to maximal prefix codes. We moreover consider two special cases of codes: maximal uniform codes and a class of codes, that we name string-codes. We show that they represent, for maximal codes, the extreme cases with regard to the number of states in terms of different sizes. Moreover we prove that prefix codes corresponding to isomorphic trees have transducers that are isomorphic as unlabeled graphs.

UR - http://hdl.handle.net/10447/75585

UR - http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8553465

M3 - Article

VL - 46

SP - 315

EP - 328

JO - RAIRO - Theoretical Informatics and Applications

JF - RAIRO - Theoretical Informatics and Applications

SN - 0988-3754

ER -