Search results for " Turing"
showing 10 items of 21 documents
Super-critical and sub-critical bifurcations in a reaction-diffusion Schnakenberg model with linear cross-diffusion
2016
In this paper the Turing pattern formation mechanism of a two components reaction-diffusion system modeling the Schnakenberg chemical reaction is considered. In Ref. (Madzavamuse et al., J Math Biol 70(4):709–743, 2015) it was shown how the presence of linear cross-diffusion terms favors the destabilization of the constant steady state. We perform the weakly nonlinear multiple scales analysis to derive the equations for the amplitude of the Turing patterns and to show how the cross-diffusion coefficients influence the occurrence of super-critical or sub-critical bifurcations. We present a numerical exploration of far from equilibrium regimes and prove the existence of multistable stationary…
The Life, Death and Miracles of Alan Mathison Turing
2010
The life of Alan Turing is described in many biographies. The best and most encyclopaedic of these is that of Andrew Hodges; quite pleasant is the agile volume by Gianni Rigamonti, Turing, il genio e lo scandalo (Flaccovio editore, Palermo, 1991). Both of these also make mention of his tragic end, which certainly casts a shadow on the mores English society at the time; but of course, who knows how other societies might have behaved?
Vita, morte e miracoli di Alan Mathison Turing
2007
La vita di Turing si puo leggere in molte biografie: ottima ed enciclopedica quella di Andrew Hodges (pubblicata in Italia da Bollati Boringhieri); molto piacevole l’agile libretto di Gianni Rigamonti, Turing, il genio e lo scandalo (Flaccovio editore, Palermo, 1991). In entrambi i libri si possono anche trovare cenni alla sua tragica fine, della quale la societa inglese di quel tempo non puo certo menar vanto; ma chissa come si sarebbero comportate altre societa.
Io Robot, la (fanta)scienza e le altre
2009
Presentazione in termini accessibili a un vasto pubblico di alcuni problemi centrali della robotica, l'intelligenza atificiale, la teoria della calcolabilità con cenni alla vita di A. M. Turing.
Dynamics of Pattern Formation in Biomimetic Systems
2008
This paper is an attempt to conceptualize pattern formation in self-organizing systems and, in particular, to understand how structures, oscillations or waves arise in a steady and homogenous environment, a phenomenon called symmetry breaking. The route followed to develop these ideas was to couple chemical oscillations produced by Belousov-Zhabotinsky reaction with confined reaction environments, the latter being an essential requirement for any process of Life. Special focus was placed on systems showing organic or lipidic compartments, which represent more reliable biomimetic matrices.
Ultrametric Finite Automata and Turing Machines
2013
We introduce a notion of ultrametric automata and Turing machines using p-adic numbers to describe random branching of the process of computation. These automata have properties similar to the properties of probabilistic automata but complexity of probabilistic automata and complexity of ultrametric automata can differ very much.
Quantum Real - Time Turing Machine
2001
The principles of quantum computation differ from the principles of classical computation very much. Quantum analogues to the basic constructions of the classical computation theory, such as Turing machine or finite 1-way and 2-ways automata, do not generalize deterministic ones. Their capabilities are incomparable. The aim of this paper is to introduce a quantum counterpart for real - time Turing machine. The recognition of a special kind of language, that can't be recognized by a deterministic real - time Turing machine, is shown.
Space-Efficient 1.5-Way Quantum Turing Machine
2001
1.5QTM is a sort of QTM (Quantum Turing Machine) where the head cannot move left (it can stay where it is and move right). For computations is used other - work tape. In this paper will be studied possibilities to economize work tape space more than the same deterministic Turing Machine can do (for some of the languages). As an example language (0i1i|i ≥ 0) is chosen, and is proved that this language could be recognized by deterministic Turing machine using log(i) cells on work tape , and 1.5QTM can recognize it using constant cells quantity.
Weakly nonlinear analysis of Turing patterns in a morphochemical model for metal growth
2015
We focus on the morphochemical reaction–diffusion model introduced in Bozzini et al. (2013) and carry out a nonlinear bifurcation analysis with the aim to characterize the shape and the amplitude of the patterns arising as the result of Turing instability of the physically relevant equilibrium. We perform a weakly nonlinear multiple scales analysis, and derive the normal form equations governing the amplitude of the patterns. These amplitude equations allow us to construct relevant solutions of the model equations and reveal the presence of multiple branches of stable solutions arising as the result of subcritical bifurcations. Hysteretic type phenomena are highlighted also through numerica…
Wittgenstein, Turing, and Neural Networks
2018
The main task of this paper is grounding the socio-anthropological “naturalization” of meaning operated by the later Wittgenstein in his remarks on rule-following in the Philosophical Investigations in considerations relating to models of low-level (biological) processes of imitation, training, and learning. If the operation suggested above is successful, two of its immediate consequences are that the social aspect of language can no longer be considered as a primitive notion, but needs to be placed upon, if not reduced to, a biological foundation; and that the study of thought, and, actually, of certain brain processes, becomes prior in the order of explanation to the study of language. Th…