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Deterministic blow-ups of minimal NFA's

Galina Jirásková (2006)

RAIRO - Theoretical Informatics and Applications

The paper treats the question whether there always exists a minimal nondeterministic finite automaton of n states whose equivalent minimal deterministic finite automaton has α states for any integers n and α with n ≤ α ≤ 2n. Partial answers to this question were given by Iwama, Kambayashi, and Takaki (2000) and by Iwama, Matsuura, and Paterson (2003). In the present paper, the question is completely solved by presenting appropriate automata for all values of n and α. However, in order to...

Diagonalization in proof complexity

Jan Krajíček (2004)

Fundamenta Mathematicae

We study diagonalization in the context of implicit proofs of [10]. We prove that at least one of the following three conjectures is true: ∙ There is a function f: 0,1* → 0,1 computable in that has circuit complexity 2 Ω ( n ) . ∙ ≠ co . ∙ There is no p-optimal propositional proof system. We note that a variant of the statement (either ≠ co or ∩ co contains a function 2 Ω ( n ) hard on average) seems to have a bearing on the existence of good proof complexity generators. In particular, we prove that if a minor variant...

Different time solutions for the firing squad synchronization problem on basic grid networks

Jozef Gruska, Salvatore La Torre, Margherita Napoli, Mimmo Parente (2006)

RAIRO - Theoretical Informatics and Applications

We present several solutions to the Firing Squad Synchronization Problem on grid networks of different shapes. The nodes are finite state processors that work in unison with other processors and in synchronized discrete steps. The networks we deal with are: the line, the ring and the square. For all of these models we consider one- and two-way communication modes and we also constrain the quantity of information that adjacent processors can exchange at each step. We first present synchronization...

Digits and continuants in euclidean algorithms. Ergodic versus tauberian theorems

Brigitte Vallée (2000)

Journal de théorie des nombres de Bordeaux

We obtain new results regarding the precise average-case analysis of the main quantities that intervene in algorithms of a broad Euclidean type. We develop a general framework for the analysis of such algorithms, where the average-case complexity of an algorithm is related to the analytic behaviour in the complex plane of the set of elementary transformations determined by the algorithms. The methods rely on properties of transfer operators suitably adapted from dynamical systems theory and provide...

Distance desert automata and the star height problem

Daniel Kirsten (2005)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

We introduce the notion of nested distance desert automata as a joint generalization of distance automata and desert automata. We show that limitedness of nested distance desert automata is PSPACE-complete. As an application, we show that it is decidable in 2 2 𝒪 ( n ) space whether the language accepted by an n -state non-deterministic automaton is of a star height less than a given integer h (concerning rational expressions with union, concatenation and iteration), which is the first ever complexity bound...

Distance desert automata and the star height problem

Daniel Kirsten (2010)

RAIRO - Theoretical Informatics and Applications

We introduce the notion of nested distance desert automata as a joint generalization of distance automata and desert automata. We show that limitedness of nested distance desert automata is PSPACE-complete. As an application, we show that it is decidable in 22O(n) space whether the language accepted by an n-state non-deterministic automaton is of a star height less than a given integer h (concerning rational expressions with union, concatenation and iteration), which is the first ever complexity...

Currently displaying 41 – 60 of 74