10,040 research outputs found
Synthesis of Data Word Transducers
In reactive synthesis, the goal is to automatically generate an
implementation from a specification of the reactive and non-terminating
input/output behaviours of a system. Specifications are usually modelled as
logical formulae or automata over infinite sequences of signals
(-words), while implementations are represented as transducers. In the
classical setting, the set of signals is assumed to be finite. In this paper,
we consider data -words instead, i.e., words over an infinite alphabet.
In this context, we study specifications and implementations respectively given
as automata and transducers extended with a finite set of registers. We
consider different instances, depending on whether the specification is
nondeterministic, universal or deterministic, and depending on whether the
number of registers of the implementation is given or not.
In the unbounded setting, we show undecidability for both universal and
nondeterministic specifications, while decidability is recovered in the
deterministic case. In the bounded setting, undecidability still holds for
nondeterministic specifications, but can be recovered by disallowing tests over
input data. The generic technique we use to show the latter result allows us to
reprove some known result, namely decidability of bounded synthesis for
universal specifications
Synthesis of Data Word Transducers
In reactive synthesis, the goal is to automatically generate an implementation from a specification of the reactive and non-terminating input/output behaviours of a system. Specifications are usually modelled as logical formulae or automata over infinite sequences of signals (omega-words), while implementations are represented as transducers. In the classical setting, the set of signals is assumed to be finite. In this paper, we consider data omega-words instead, i.e., words over an infinite alphabet. In this context, we study specifications and implementations respectively given as automata and transducers extended with a finite set of registers. We consider different instances, depending on whether the specification is nondeterministic, universal or deterministic, and depending on whether the number of registers of the implementation is given or not.
In the unbounded setting, we show undecidability for both universal and non-deterministic specifications, while decidability is recovered in the deterministic case. In the bounded setting, undecidability still holds for non-deterministic specifications, but can be recovered by disallowing tests over input data. The generic technique we use to show the latter result allows us to reprove some known result, namely decidability of bounded synthesis for universal specifications
Morphological annotation of Korean with Directly Maintainable Resources
This article describes an exclusively resource-based method of morphological
annotation of written Korean text. Korean is an agglutinative language. Our
annotator is designed to process text before the operation of a syntactic
parser. In its present state, it annotates one-stem words only. The output is a
graph of morphemes annotated with accurate linguistic information. The
granularity of the tagset is 3 to 5 times higher than usual tagsets. A
comparison with a reference annotated corpus showed that it achieves 89% recall
without any corpus training. The language resources used by the system are
lexicons of stems, transducers of suffixes and transducers of generation of
allomorphs. All can be easily updated, which allows users to control the
evolution of the performances of the system. It has been claimed that
morphological annotation of Korean text could only be performed by a
morphological analysis module accessing a lexicon of morphemes. We show that it
can also be performed directly with a lexicon of words and without applying
morphological rules at annotation time, which speeds up annotation to 1,210
word/s. The lexicon of words is obtained from the maintainable language
resources through a fully automated compilation process
Lipschitz Robustness of Finite-state Transducers
We investigate the problem of checking if a finite-state transducer is robust
to uncertainty in its input. Our notion of robustness is based on the analytic
notion of Lipschitz continuity --- a transducer is K-(Lipschitz) robust if the
perturbation in its output is at most K times the perturbation in its input. We
quantify input and output perturbation using similarity functions. We show that
K-robustness is undecidable even for deterministic transducers. We identify a
class of functional transducers, which admits a polynomial time
automata-theoretic decision procedure for K-robustness. This class includes
Mealy machines and functional letter-to-letter transducers. We also study
K-robustness of nondeterministic transducers. Since a nondeterministic
transducer generates a set of output words for each input word, we quantify
output perturbation using set-similarity functions. We show that K-robustness
of nondeterministic transducers is undecidable, even for letter-to-letter
transducers. We identify a class of set-similarity functions which admit
decidable K-robustness of letter-to-letter transducers.Comment: In FSTTCS 201
A Finite State and Data-Oriented Method for Grapheme to Phoneme Conversion
A finite-state method, based on leftmost longest-match replacement, is
presented for segmenting words into graphemes, and for converting graphemes
into phonemes. A small set of hand-crafted conversion rules for Dutch achieves
a phoneme accuracy of over 93%. The accuracy of the system is further improved
by using transformation-based learning. The phoneme accuracy of the best system
(using a large set of rule templates and a `lazy' variant of Brill's algoritm),
trained on only 40K words, reaches 99% accuracy.Comment: 8 page
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