Research in non-classical and emergent computing paradigms, architectures and implementations focuses on deriving novel information processing principles from laws and phenomena observed in physical, chemical and biological systems. A further goal is to uncover new theories and to go beyond classical computer science. The research also aims to uncover novel theoretical constructs not yet established, or never heard of before, in the classical computer science. The goal of this special issue is to give readers a snapshot of the current state in this exciting field of research. We have selected four papers in the areas of social insects computation, artificial chemistry, systems biology, and quantum computation.
Marcus Komann and Dietmar Fey (Friedrich-Schiller University Jena, Germany) apply findings from ant-based computing and cellular automata to design algorithms for image pre-processing In their paper “Realising Emergent Image Preprocessing Tasks in Cellular-Automaton-Alike Massively Parallel Hardware” they discuss how image reduction can be implemented by swarms of “marching pixels” and they discuss the complexity of the implementation. They also present the architecture of a grid-like processor, which can directly implement their algorithms in hardware.
Yasuhiro Suzuki (Nagoya University, Japan) explores artificial chemistries and studies abstract rewriting systems on multi-sets (ARMS), where molecules of an abstract chemical solution are represented by finite sets and reactions between the molecules are seen as transformations of the sets. His paper “An Investigation of the Brusselator on the Mesoscopic Scale” discusses the advantages of the ARMS based computations and demonstrates by means of an example natural spatial processes, namely the inflammatory reactions in immune system and the dynamics in excitable chemical systems (Belousov–Zhabotinsky reactions).
In his paper “Systemic Computation: A Model of Interacting Systems with Natural Characteristics,” Peter J. Bentley (University College London, UK) speculates that biological systems can be formalised by graphs of interactions. He then expands the idea to the field of computation by building a systematic computer theory. Bentley's systematic computer is a nested structure of systems, which interact with each other and thus get altered, but never destroyed. The systems' transformation can be interpreted as a computation.
Relations between classical and quantum models of computation are analysed in the paper “Quantum Computing: Beyond the Limits of Conventional Computation” by Marius Nagy and Selim G. Akl (Queen's University, Canada). They give a brief overview of current findings in quantum computation, compare the quantum Turing machine with its deterministic and probabilistic counterpart, tackle quantum distinguishability, and finally show that the set of functions computed by a classical Turing machine is a subset of those computed by its quantum relative.
We hope that this special issue will further and open the dialog between the field of classical and non-classical computation and other sciences and will help to make the field more mature. What is considered unconventional today might simply become conventional tomorrow, thus the necessity to keep our eyes open but to be critical at the same time.