1,037 research outputs found
Scale-invariant cellular automata and self-similar Petri nets
Two novel computing models based on an infinite tessellation of space-time
are introduced. They consist of recursively coupled primitive building blocks.
The first model is a scale-invariant generalization of cellular automata,
whereas the second one utilizes self-similar Petri nets. Both models are
capable of hypercomputations and can, for instance, "solve" the halting problem
for Turing machines. These two models are closely related, as they exhibit a
step-by-step equivalence for finite computations. On the other hand, they
differ greatly for computations that involve an infinite number of building
blocks: the first one shows indeterministic behavior whereas the second one
halts. Both models are capable of challenging our understanding of
computability, causality, and space-time.Comment: 35 pages, 5 figure
A guided tour of asynchronous cellular automata
Research on asynchronous cellular automata has received a great amount of
attention these last years and has turned to a thriving field. We survey the
recent research that has been carried out on this topic and present a wide
state of the art where computing and modelling issues are both represented.Comment: To appear in the Journal of Cellular Automat
A Quantum Game of Life
This research describes a three dimensional quantum cellular automaton (QCA)
which can simulate all other 3D QCA. This intrinsically universal QCA belongs
to the simplest subclass of QCA: Partitioned QCA (PQCA). PQCA are QCA of a
particular form, where incoming information is scattered by a fixed unitary U
before being redistributed and rescattered. Our construction is minimal amongst
PQCA, having block size 2 x 2 x 2 and cell dimension 2. Signals, wires and
gates emerge in an elegant fashion.Comment: 13 pages, 10 figures. Final version, accepted by Journ\'ees Automates
Cellulaires (JAC 2010)
Frontiers of Membrane Computing: Open Problems and Research Topics
This is a list of open problems and research topics collected after the Twelfth
Conference on Membrane Computing, CMC 2012 (Fontainebleau, France (23 - 26 August
2011), meant initially to be a working material for Tenth Brainstorming Week on
Membrane Computing, Sevilla, Spain (January 30 - February 3, 2012). The result was
circulated in several versions before the brainstorming and then modified according to
the discussions held in Sevilla and according to the progresses made during the meeting.
In the present form, the list gives an image about key research directions currently active
in membrane computing
Quantitative reactive modeling and verification
Formal verification aims to improve the quality of software by detecting errors before they do harm. At the basis of formal verification is the logical notion of correctness, which purports to capture whether or not a program behaves as desired. We suggest that the boolean partition of software into correct and incorrect programs falls short of the practical need to assess the behavior of software in a more nuanced fashion against multiple criteria. We therefore propose to introduce quantitative fitness measures for programs, specifically for measuring the function, performance, and robustness of reactive programs such as concurrent processes. This article describes the goals of the ERC Advanced Investigator Project QUAREM. The project aims to build and evaluate a theory of quantitative fitness measures for reactive models. Such a theory must strive to obtain quantitative generalizations of the paradigms that have been success stories in qualitative reactive modeling, such as compositionality, property-preserving abstraction and abstraction refinement, model checking, and synthesis. The theory will be evaluated not only in the context of software and hardware engineering, but also in the context of systems biology. In particular, we will use the quantitative reactive models and fitness measures developed in this project for testing hypotheses about the mechanisms behind data from biological experiments
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