International Workshop on Theoretical Computer Science

Dedicated to Prof. Cristian S. Calude's 60th Birthday

  Dates and scope

The Workshop took place between February 21 and February 24, 2012 in Auckland, New Zealand. The volume titled Computation, Physics and Beyond, based on the WTCS2012, was published in the LNCS Festschrifts Series of Springer. The volume contains contributions from invited speakers and regular papers that present either expository/survey results or original research in the following areas (in which Cristian S. Calude has had significant contributions):
  • Algorithmic information theory
  • Algorithms
  • Automata and formal languages
  • Automata, logic, and applications
  • Computing and natural sciences
  • Computability and applications
  • Philosophy of computation
  • Physics and computation
  • Unconventional models of computation

  Festschrift volume

This Festschrift volume has been published in honour of Cristian Calude on the occasion of his 60th birthday and contains contributions presented at the International Workshop on Theoretical Computer Science, WTCS 2012.
Cristian Calude has made a significant contribution to research in computer science theory. Along with early work by Chaitin, Kucera, Kurtz, Solovay, and Terwijn his papers published in the mid-1990s jointly with Khoussainov, Hertling, and Wang laid the foundation for the development of modern theory of algorithmic randomness. His work was essential for establishing the leading role of New Zealand in this area.
The research interests of Cristian Calude are reflected in the topics covered by the 32 papers included in this book. They have been organised into four parts. The first part consists of papers discussing his life achievements. This is followed by papers in the three general areas of complexity, computability, and randomness; physics, philosophy (and logic), and computation; and algorithms, automata, and formal models (including unconventional computing).

  Table of contents

The Art of Reaching the Age of Sixty.- Calude as Father of One of the Computer Science Journals.- Random Semicomputable Reals Revisited.- Constructing the In mum of Two Projections.- Bounded Randomness.- A Note on Blum Static Complexity Measures.- A Program-Size Complexity Measure for Mathematical Problems and Conjectures.- On Degrees of Randomness and Genetic Randomness.- Hartmanis-Stearns Conjecture on Real Time and Transcendence.- Learning Families of Closed Sets in Matroids.- Invariance and Universality of Complexity.- Demuth's Path to Randomness (extended abstract).- Correcting Codes.- Some Transfinite Generalisations of Godel's Incompleteness Theorem.- Phase Transition between Unidirectionality and Bidirectionality.- Computer Runtimes and the Length of Proofs.- Symmetry of Information: A Closer Look.- How Much Information Can There Be in a Real Number?.- Mathematics, Metaphysics and the Multiverse.- Exponential Decay in Quantum Mechanics.- Randomness Increases Order in Biological Evolution.- Haunted Quantum Contextuality Versus Value Indefiniteness.- Outerplanar Graphs and Delaunay Triangulations.- Representing Reaction Systems by Trees.- Derivatives of Regular Expressions and An Application.- Triangular and Hexagonal Tile Self-Assembly Systems.- dP Automata versus Right-Linear Simple Matrix Grammars.- State Complexity of Kleene-Star Operations on Trees.- Composition Sequences and Synchronizing Automata.- On the Connected Partition Dimension of a Wheel Related Graph.


  Conference dinner

Mecca Devonport, 1 Victoria Road, Devonport.
Photos (slideshow MP4 format) by Elena and Andreea, Karl Svozil and Helmut Jürgensen. Cris' speech.

  Links to slides, blogs and other information related to WTCS2012

  • The official conference group photo, a collection of general photos (by Karl and Cris), and Cezar.
  • Some speaker photos.

      Organizing committee

    M.J. Dinneen, G. Dobbie, R. Doran, B. Khoussainov and A. Nies.

      Program committee

    B. Cooper, F. Costa, M.J. Dinneen, P. Hertling, B. Khoussainov (chair), F. Kroon, Y. Matiyasevich, A. Nies, Gh. Păun, G. Rozenberg, K. Salomaa, L. Staiger, A. Shen, F. Stephan and M. Zimand.

      Editorial committee

    M.J. Dinneen, B. Khoussainov and A. Nies.