2,244 research outputs found
The complexity of small universal Turing machines : a survey
No full textWe survey some work concerned with small universal Turing machines, cellular automata, tag systems, and other simple models of computation. For example it has been an open question for some time as to whether the smallest known universal Turing machines of Minsky, Rogozhin, Baiocchi and Kudlek are efficient (polynomial time) simulators of Turing machines. These are some of the most intuitively simple computational devices and previously the best known simulations were exponentially slow. We discuss recent work that shows that these machines are indeed efficient simulators. In addition, another related result shows that Rule 110, a well-known elementary cellular automaton, is efficiently universal. We also discuss some old and new universal program size results, including the smallest known universal Turing machines. We finish the survey with results on generalised and restricted Turing machine models including machines with a periodic background on the tape (instead of a blank symbol), multiple tapes, multiple dimensions, and machines that never write to their tape. We then discuss some ideas for future work.Science Foundation IrelandExtended version of Theoretical Computer Science 410(4-5), Feburary 2009, pp 443-450 so I'm adding doi and rights info for Elsevier: not sure if that's right? - AV 11/10/2011
ke - kpw10/11/1
First, Scale Up to the Robotic Turing Test, Then Worry About Feeling
No full textConsciousness is feeling, and the problem of consciousness is the problem of explaining how and why some of the functions underlying some of our performance capacities are felt rather than just “functed.” But unless we are prepared to assign to feeling a telekinetic power (which all evidence contradicts), feeling cannot be assigned any causal power at all. We cannot explain how or why we feel. Hence the empirical target of cognitive science can only be to scale up to the robotic Turing Test, which is to explain all of our performance capacity, but without explaining consciousness or incorporating it in any way in our functional explanation
Digitising the Turing Archive: A Pilot Study
No full textThis report presents a summary of the pilot project to produce an on-line version of a selected portion of the archive of Alan Turing held at King’s College, Cambridge. The design and creation of a database making use of information held in the archive catalogue is discussed. The production of a Web based interface to access the on-line materials is described. The practical issues involved in digitising documents are covered and the lessons learnt from this process are included. Finally, the report also presents an effort model, and sample timings from which cost estimates can be obtained
Linguaggio, logica e matematica in A. Turing
No full textSi analizzano i lavori di Turing sulla teoria dei tipi nella pratica matematica alla luce dell'intergioco tra uso di strutture astratte (ad es. gruppi) e situazioni in cui compaiono casi concreti (ad es. gruppi finiti) di queste strutture e si sottolinea come la prospettiva di Turing si possano considerare alla luce di alcuni recenti sviluppi della Teoria dei Modelli
Turing instabilities in general systems
No full textWe present necessary and sufficient conditions on the stability matrix of a general n(S2)-dimensional reaction-diffusion system which guarantee that its uniform steady state can undergo a Turing bifurcation. The necessary (kinetic) condition, requiring that the system be composed of an unstable (or activator) and a stable (or inhibitor) subsystem, and the sufficient condition of sufficiently rapid inhibitor diffusion relative to the activator subsystem are established in three theorems which form the core of our results. Given the possibility that the unstable (activator) subsystem involves several species (dimensions), we present a classification of the analytically deduced Turing bifurcations into p (1 h p h (n m 1)) different classes. For n = 3 dimensions we illustrate numerically that two types of steady Turing pattern arise in one spatial dimension in a generic reaction-diffusion system. The results confirm the validity of an earlier conjecture [12] and they also characterise the class of so-called strongly stable matrices for which only necessary conditions have been known before [23, 24]. One of the main consequences of the present work is that biological morphogens, which have so far been expected to be single chemical species [1-9], may instead be composed of two or more interacting species forming an unstable subsystem
Turing Machine
No full textThe Turing Machine Cross media concept is based on the life of Alan Turing (1912-1954), who was a wartime code-breaker and pioneer of computer science – often considered the father of modern computing. He made a significant and provocative contribution to the debate regarding artificial intelligence: whether it will ever be possible to say that a machine is conscious and can think. Alan01 installation (which Tuomola has co-dramatised) & Turing Machine multimedia opera (in which he co-produced the 3D set) are still touring the world (2013-2014), as one can read it the news items in the end of the transmedia production desciptuion)
Bringing Up Turing's 'Child-Machine' (revised)
No full textAbstract. Turing wrote that the "guiding principle" of his investigation into the possibility of intelligent machinery was "The analogy [of machinery that might be made to show intelligent behavior] with the human brain." (Turing 1948) In his discussion of the investigations that Turing said were guided by this analogy, however, he employs a more far-reaching analogy: he eventually expands the analogy from the human brain out to "the human community as a whole." Along the way, he takes note of an obvious fact in the bigger scheme of things regarding human intelligence: grownups were once children; this leads him to imagine what a machine analogue of childhood might be. In this paper, I'll discuss Turing's child-machine, what he said about different ways of educating it, and what impact the "bringing up" of a child-machine has on its ability to behave in ways that might be taken for intelligent. I'll also discuss how some of the various games he suggested humans might play with machines are related to this approach
Spatial behavioural responses to the spread of an infectious disease can suppress Turing and Turing–Hopf patterning of the disease
No full textReducing risky behaviour and/or avoiding sites where the risk of infection is perceived as higher (by social and/or spatial distancing) represent the two main forms of non-pharmaceutical behavioural responses of humans to the threats of infectious diseases. Here we investigate, within a reaction–diffusion setting, a family of new models for an endemic SIR (susceptible–infective–removed) infectious disease for which no vaccine is available and individuals’ responses to the infection threat are entirely based on changes either in their social behaviour or in their mobility behaviour, that is avoiding to visit sites with a large infection prevalence. First, we derive general conditions for the onset of Turing patterns for a general family of spatially inhomogeneous SIR models with a prevalence-dependent contact rate and constant recruitment. Then, we characterize our main family of models where the behavioural response also includes a spatial component, and show the condition bringing to the mitigation, or even the destruction, of Turing patterns. The same conditions can allow the transition from Turing–Hopf spatio-temporal patterns to pure Hopf temporal patterns. The same is also done for two SIS models. These results bring an inference of interest: the reduction of spatial clustering typically observed during the course of an epidemics might be related to a combination of agents’ spontaneous social and spatial distancing. To validate our theoretical results and further explore other spatio-temporal effects of the proposed spatial behavioural responses, numerical simulations of a specific instance of the above-mentioned family of SIR models have been performed
Multi species turing patterns in three dimensions
No full textIn 1952, Alan M. Turing presented a reaction-diffusion model that described formation of skin patterns. The patterns he predicted have later been found in various natural phenomena, such as in skins of fish or even in vegetation around termite hills. His patterns have even been taken to the micro-level. In 1984, David A. Young proposed a discretisation of this model, which enabled computer simulation. Both Turing and Young had only looked at two-dimensional patterns, until Martin Skrodzki and Konrad Polthier took the patterns to the third dimension in 2017. In this paper, these 3D simulations are generalised to produce patterns with more than two substances. We want to see whether Turing-like patterns also emerge there. To increase simulation speeds, a Graphics Processing Unit (GPU) implementation is described for this multi-species extension. Furthermore, we begin to investigate to what extent an order parameter can be defined, to analyse the formation of 3D structures. We found that our multi-species extension produced Turing-like structures that look similar to the ones found by former models. Our GPU simulation provided a significant performance increase. We also found that our order parameter can distinguish between well-mixed, well-segregated, and fully dominated states. However, it is yet unclear whether it can also be used to classify shapes.CSE3000 Research ProjectComputer Science and Engineerin
Spikes for the gierer-meinhardt system with many segments of different diffusivities
No full textWe rigorously prove results on spiky patterns for the
Gierer-Meinhardt system with a large number of jump
discontinuities in the diffusion coefficient of the inhibitor. Using
numerical computations in combination with a Turing-type instability
analysis, this system has been investigated by Benson, Maini and
Sherratt
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