Jobs/M2 AD 2015 Vcsn for Linguists

	Vcsn for Linguists
Reference id	M2 AD 2015 Vcsn for Linguists
Dates	5-6 months in 2015
Research field	Automata Theory
Related project	Vaucanson
Advisor	Akim Demaille
General presentation of the field	The classical theory of automata, of transducers and of rational expressions, admits a very elegant and extremely useful extension (eg, in natural language processing) taking into account the concept of weighting. The weights are then taken in a semiring, which can be classical (⟨𝔹, ∨, ∧⟩, ⟨ℤ, +, ×⟩, ⟨ℚ, +, ×⟩, etc..), tropical (⟨ℤ, min, +⟩, etc..), or yet of another type (e.g. rational expressions). Automata are heavily used in computational linguistics, and conversely, automata used in computational linguistics are "heavy". Vcsn is a project led by Alexandre Duret-Lutz and Akim Demaille (LRDE). It is a platform for the manipulation of automata, transducers and weighted rational expressions. It is written in C++11 avoiding the classical object-oriented programming in favor of generic programming (template) for more performance. Vcsn is an heir of the Vaucanson 2 project which was developed in partnership with Jacques Sakarovitch (Telecom ParisTech) and Sylvain Lombardy (LaBRI). Vcsn has a sound base of data structure and algorithms for automata and rational expressions. It is already able to deal with many of the typical needs of linguists. However some specific semirings have not been implemented, and some well-known algorithms are needed.
Prerequisites	good programmer in some language acquaintance with C++ facilities with theoretical matters
Objectives	The objective of this internship is to develop a complete Computational Linguistics toolchain on top of Vcsn, for instance the "SMS to French" project from François Yvon (sms.limsi.fr). To this end, Vcsn will have to be completed with the needed data structures and algorithms, and possibly the existing implementation will have to be overhauled to cope with the extremely demanding size of these real-life automata.
Benefit for the candidate
References	Jacques Sakarovitch, “Elements of Automata Theory,” Cambridge University Press. Akim Demaille, Alexandre Duret-Lutz, Sylvain Lombardy, Jacques Sakarovitch. “Implementation Concepts in Vaucanson 2,” CIAA’13.
Place	LRDE: How to get to us
Compensation	1000 € gross/month
Future work opportunities
Contact	<akim at lrde . epita . fr> <akim at lrde . epita . fr>