Titlebook: Developments in Language Theory; 11th International C Tero Harju,Juhani Karhumäki,Arto Lepistö Conference proceedings 2007 Springer-Verlag

千篇一律

Multi-letter Reversible and Quantum Finite Automatanizable by a one-way quantum finite automaton (QFA). Up to now, there have been introduced many different models of QFAs, with increasing capabilities, but none of them can cope with this language..We introduce a new, quite simple modification of the QFA model (actually even a deterministic reversib

CEDE

Approximability and Non-approximability Results in Computing the Mean Speedup of Trace Monoids under two conditions: (1) uniform distribution on the words of given length and (2) uniform distribution on the traces of given height. In the first case, we give an approximability result showing a probabilistic fully polynomial time approximation scheme, while, in the second case, we prove that t

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Lament

Two Element Unavoidable Sets of Partial Wordsnection to the study of combinatorics on words. The theory of unavoidable sets has seen extensive study over the past twenty years. In this paper we extend the definition of unavoidable sets of words to unavoidable sets of partial words. Partial words, or finite sequences that may contain a number o

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cartilage

Characterizing Reduction Graphs for Gene Assembly in Ciliateslled legal strings. It has been shown that reduction graphs, graphs that are based on the notion of breakpoint graph in the theory of sorting by reversal, for legal strings provide valuable insights into the gene assembly process. We characterize which legal strings obtain the same reduction graph (

Eclampsia

2-Visibly Pushdown Automata, namely .. These automata introduce a useful model to effectively describe concurrent pushdown systems using a simple communication mechanism between stacks. We show that 2-VPA are strictly more expressive than VPA. Indeed, 2-VPA accept some context-sensitive languages that are not context-free and

轻推

An Efficient Computation of the Equation ,-Automaton of a Regular ,-Expressionkarovitch. Our construction is based on an extension to regular .-expressions of the notion of c-continuation that we introduced to compute the equation automaton of a regular expression as a quotient of its position automaton.

insidious

An Extension of Newton’s Method to ,-Continuous Semiringssemiring of the real numbers can be solved numerically using Newton’s method. We generalize the method to any .-continuous semiring and show that it converges faster to the least fixed point than the Kleene sequence ., ., .(.),... We prove that the Newton approximants in the semiring of languages co

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