Machines, Computations, and Universality

In the ?rst part of the present volume of LNCS, the reader will ?nd the invited talks given at the MCU 2001 conference. In the second part, he/she will ?nd the contributions that were presented at the conference after selection. In both cases, papers are arranged in the alphabetical order of the authors. MCU 2001 is the third conference in theoretical computer science, Machines, computations and universality, formerly, Machines et calculs universels. Both previous conferences, MCU'95 and MCU'98, were organized by Maurice M- genstern in Paris and in Metz (France), respectively. From the very beginning, MCU conferences have been an international sci- ti?c event. For the third conference, in order to stress that aspect, it was decided to hold it outside France. Moldova was chosen thanks to the close cooperation between the present chairmen of MCU 2001. MCU 2001 also aims at high scienti?c standards. We hope that the present volume will convince the reader that the tradition of previous conferences have been upheld by this one. Cellular automata and molecular computing are well represented in this volume. And this is also the case for quantum computing, f- mal languages, and the theory of automata. MCU 2001 does not fail its tradition of providing our community with important results on Turing machines.

Inhalt

Invited Lectures Notes.- Three Small Universal Turing Machines.- Computation in Gene Networks.- Power, Puzzles and Properties of Entanglement.- Combinatorial and Computational Problems on Finite Sets of Words.- Computing with Membranes (P Systems): Universality Results.- A Simple Universal Logic Element and Cellular Automata for Reversible Computing.- Some Applications of the Decidability of DPDA's Equivalence.- The Equivalence Problem for Computational Models: Decidable and Undecidable Cases.- Two Normal Forms for Rewriting P Systems.- Technical Contributions.- On a Conjecture of K?rka. A Turing Machine with No Periodic Configurations.- On the Transition Graphs of Turing Machines.- JC-Nets.- JC-Nets.- Nonterminal Complexity of Programmed Grammars.- Nonterminal Complexity of Programmed Grammars.- On the Number of Non-Terminal Symbols in Graph-Controlled, Programmed and Matrix Grammars.- On the Number of Non-Terminal Symbols in Graph-Controlled, Programmed and Matrix Grammars.- A Direct Construction of a Universal Extended H System.- A Direct Construction of a Universal Extended H System.- Speeding-Up Cellular Automata by Alternations.- Speeding-Up Cellular Automata by Alternations.- Efficient Universal Pushdown Cellular Automata and Their Application to Complexity.- Efficient Universal Pushdown Cellular Automata and Their Application to Complexity.- Firing Squad Synchronization Problem on Bidimensional Cellular Automata with Communication Constraints.- Firing Squad Synchronization Problem on Bidimensional Cellular Automata with Communication Constraints.- P Systems with Membrane Creation: Universality and Efficiency.- P Systems with Membrane Creation: Universality and Efficiency.- On the Computational Power of a Continuous-space Optical Model of Computation.- On the Computational Power of a Continuous-space Optical Model of Computation.- On a P-optimal Proof System for the Set of All Satisfiable Boolean Formulas (SAT).- On a P-optimal Proof System for the Set of All Satisfiable Boolean Formulas (SAT).- D0L System + Watson-Crick Complementarity = Universal Computation.- D0L System + Watson-Crick Complementarity = Universal Computation.