514 research outputs found
COMPUTER SIMULATION AND COMPUTABILITY OF BIOLOGICAL SYSTEMS
The ability to simulate a biological organism by employing a computer is related to the
ability of the computer to calculate the behavior of such a dynamical system, or the "computability" of the system.* However, the two questions of computability and simulation are not equivalent. Since the question of computability can be given a precise answer in terms of recursive functions, automata theory and dynamical systems, it will be appropriate to consider it first. The more elusive question of adequate simulation of biological systems by a computer will be then addressed and a possible connection between the two answers given will be considered. A conjecture is formulated that suggests the possibility of employing an algebraic-topological, "quantum" computer (Baianu, 1971b)
for analogous and symbolic simulations of biological systems that may include chaotic processes that are not, in genral, either recursively or digitally computable. Depending on the biological network being modelled, such as the Human Genome/Cell Interactome or a trillion-cell Cognitive Neural Network system, the appropriate logical structure for such simulations might be either the Quantum MV-Logic (QMV) discussed in recent publications (Chiara, 2004, and references cited therein)or Lukasiewicz Logic Algebras that were shown to be isomorphic to MV-logic algebras (Georgescu et al, 2001)
Multidimensional cellular automata and generalization of Fekete's lemma
Fekete's lemma is a well known combinatorial result on number sequences: we
extend it to functions defined on -tuples of integers. As an application of
the new variant, we show that nonsurjective -dimensional cellular automata
are characterized by loss of arbitrarily much information on finite supports,
at a growth rate greater than that of the support's boundary determined by the
automaton's neighbourhood index.Comment: 6 pages, no figures, LaTeX. Improved some explanations; revised
structure; added examples; renamed "hypercubes" into "right polytopes"; added
references to Arratia's paper on EJC, Calude's book, Cook's proof of Rule 110
universality, and arXiv paper 0709.117
Integrating a Non-Uniformly Sampled Software Retina with a Deep CNN Model
We present a biologically inspired method for pre-processing images applied to CNNs
that reduces their memory requirements while increasing their invariance to scale and rotation
changes. Our method is based on the mammalian retino-cortical transform: a
mapping between a pseudo-randomly tessellated retina model (used to sample an input
image) and a CNN. The aim of this first pilot study is to demonstrate a functional retinaintegrated
CNN implementation and this produced the following results: a network using
the full retino-cortical transform yielded an F1 score of 0.80 on a test set during a 4-way
classification task, while an identical network not using the proposed method yielded an
F1 score of 0.86 on the same task. The method reduced the visual data by e×7, the input
data to the CNN by 40% and the number of CNN training epochs by 64%. These results
demonstrate the viability of our method and hint at the potential of exploiting functional
traits of natural vision systems in CNNs
A Survey of Cellular Automata: Types, Dynamics, Non-uniformity and Applications
Cellular automata (CAs) are dynamical systems which exhibit complex global
behavior from simple local interaction and computation. Since the inception of
cellular automaton (CA) by von Neumann in 1950s, it has attracted the attention
of several researchers over various backgrounds and fields for modelling
different physical, natural as well as real-life phenomena. Classically, CAs
are uniform. However, non-uniformity has also been introduced in update
pattern, lattice structure, neighborhood dependency and local rule. In this
survey, we tour to the various types of CAs introduced till date, the different
characterization tools, the global behaviors of CAs, like universality,
reversibility, dynamics etc. Special attention is given to non-uniformity in
CAs and especially to non-uniform elementary CAs, which have been very useful
in solving several real-life problems.Comment: 43 pages; Under review in Natural Computin
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