Results 1  10
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24
FiniteState Transducers
 in Speech Recognition. Computer Speech and Language
, 1997
"... Abstract. psubsequential transducers are efficient finitestate transducers with p final outputs used in a variety of applications. Not all transducers admit equivalent psubsequential transducers however. We briefly describe an existing generalized determinization algorithm for psubsequential tran ..."
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Cited by 69 (19 self)
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Abstract. psubsequential transducers are efficient finitestate transducers with p final outputs used in a variety of applications. Not all transducers admit equivalent psubsequential transducers however. We briefly describe an existing generalized determinization algorithm for psubsequential transducers and give the first characterization of psubsequentiable transducers, transducers that admit equivalent psubsequential transducers. Our characterization shows the existence of an efficient algorithm for testing psubsequentiability. We have fully implemented the generalized determinization algorithm and the algorithm for testing psubsequentiability. We report experimental results showing that these algorithms are practical in largevocabulary speech recognition applications. The theoretical formulation of our results is the equivalence of the following three properties for finitestate transducers: determinizability in the sense of the generalized algorithm, psubsequentiability, and the twins property. 1
Minimization Algorithms for Sequential Transducers
, 2000
"... We present general algorithms for minimizing sequential finitestate transducers that output strings or numbers. The algorithms are shown to be efficient since in the case of acyclic transducers and for output strings they operate in O(S+E+V+(EV+F)x(Pmax+1)) steps, where S is the sum of ..."
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Cited by 55 (12 self)
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We present general algorithms for minimizing sequential finitestate transducers that output strings or numbers. The algorithms are shown to be efficient since in the case of acyclic transducers and for output strings they operate in O(S+E+V+(EV+F)x(Pmax+1)) steps, where S is the sum of the lengths of all output labels of the resulting transducer, E the set of transitions of the given transducer, V the set of its states, F the set of final states, and Pmax one of the longest of the longest common prefixes of the output paths leaving each state of the transducer. The algorithms apply to a larger class of transducers which includes subsequential transducers.
FSA Utilities: A Toolbox to Manipulate Finitestate Automata
 Automata Implementation
, 1997
"... This paper describes the FSA Utilities toolbox: a collection of utilities to manipulate finitestate automata and finitestate transducers. Manipulations include determinization (both for finitestate acceptors and finitestate transducers), minimization, composition, complementation, intersection, ..."
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Cited by 23 (3 self)
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This paper describes the FSA Utilities toolbox: a collection of utilities to manipulate finitestate automata and finitestate transducers. Manipulations include determinization (both for finitestate acceptors and finitestate transducers), minimization, composition, complementation, intersection, Kleene closure, etc. Furthermore, various visualization tools are available to browse finitestate automata. The toolbox is implemented in SICStus Prolog.
On the Determinization of Weighted Finite Automata
 SIAM J. Comput
, 1998
"... . We study determinization of weighted finitestate automata (WFAs), which has important applications in automatic speech recognition (ASR). We provide the first polynomialtime algorithm to test for the twins property, which determines if a WFA admits a deterministic equivalent. We also provide ..."
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Cited by 16 (0 self)
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. We study determinization of weighted finitestate automata (WFAs), which has important applications in automatic speech recognition (ASR). We provide the first polynomialtime algorithm to test for the twins property, which determines if a WFA admits a deterministic equivalent. We also provide a rigorous analysis of a determinization algorithm of Mohri, with tight bounds for acyclic WFAs. Given that WFAs can expand exponentially when determinized, we explore why those used in ASR tend to shrink. The folklore explanation is that ASR WFAs have an acyclic, multipartite structure. We show, however, that there exist such WFAs that always incur exponential expansion when determinized. We then introduce a class of WFAs, also with this structure, whose expansion depends on the weights: some weightings cause them to shrink, while others, including random weightings, cause them to expand exponentially. We provide experimental evidence that ASR WFAs exhibit this weight dependence. ...
On the Sequentiality of the Successor Function
, 1997
"... Let U be a strictly increasing sequence of integers. By a greedy algorithm, every nonnegative integer has a greedy Urepresentation. The successor function maps the greedy Urepresentation of N onto the greedy Urepresentation of N+1. We characterize the sequences U such that the successor functi ..."
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Cited by 10 (1 self)
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Let U be a strictly increasing sequence of integers. By a greedy algorithm, every nonnegative integer has a greedy Urepresentation. The successor function maps the greedy Urepresentation of N onto the greedy Urepresentation of N+1. We characterize the sequences U such that the successor function associated to U is a left, resp. a right sequential function. We also show that the odometer associated to U is continuous if and only if the successor function is right sequential.
OnLine Finite Automata for Addition in Some Numeration Systems
"... We consider numeration systems where the base is a negative integer, or a complex number which is a root of a negative integer. We give parallel algorithms for addition in these numeration systems, from which we derive online algorithms realized by finite automata. A general construction relatin ..."
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Cited by 9 (0 self)
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We consider numeration systems where the base is a negative integer, or a complex number which is a root of a negative integer. We give parallel algorithms for addition in these numeration systems, from which we derive online algorithms realized by finite automata. A general construction relating addition in base fi and addition in base fi m is given. Results on addition in base fi = m p b, where b is a relative integer, follow. We also show that addition in base the golden ratio is computable by an online finite automaton, but is not parallelizable. 1 Introduction A positional numeration system is given by a base and by a set of digits. In the most usual numeration systems, the base is an integer b 2 and the digit set is f0; : : : ; b \Gamma 1g. In order to represent complex numbers without separating the real and the imaginary part, one can use a complex base. For instance, it is known that every complex number can be expressed with base i p 2 and digit set f0; 1g (...
Determinization of Transducers Over Infinite Words
"... We study the determinization of transducers over infinite words. We consider transducers with all their states final. We give an effective characterization of sequential functions over infinite words. We also describe an algorithm to determinize transducers over infinite words. ..."
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Cited by 7 (2 self)
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We study the determinization of transducers over infinite words. We consider transducers with all their states final. We give an effective characterization of sequential functions over infinite words. We also describe an algorithm to determinize transducers over infinite words.
Deciding unambiguity and sequentiality from a finitely ambiguous maxplus automaton
 THEORET. COMPUT. SCI
, 2004
"... Finite automata with weights in the maxplus semiring are considered. The main result is: it is decidable whether a series that is recognized by a finitely ambiguous maxplus automaton is unambiguous, or is sequential. Furthermore, the proof is constructive. A collection of examples is given to illu ..."
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Cited by 5 (2 self)
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Finite automata with weights in the maxplus semiring are considered. The main result is: it is decidable whether a series that is recognized by a finitely ambiguous maxplus automaton is unambiguous, or is sequential. Furthermore, the proof is constructive. A collection of examples is given to illustrate the hierarchy of maxplus series with respect to ambiguity.