272 research outputs found

    Computation Environments, An Interactive Semantics for Turing Machines (which P is not equal to NP considering it)

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    To scrutinize notions of computation and time complexity, we introduce and formally define an interactive model for computation that we call it the \emph{computation environment}. A computation environment consists of two main parts: i) a universal processor and ii) a computist who uses the computability power of the universal processor to perform effective procedures. The notion of computation finds it meaning, for the computist, through his \underline{interaction} with the universal processor. We are interested in those computation environments which can be considered as alternative for the real computation environment that the human being is its computist. These computation environments must have two properties: 1- being physically plausible, and 2- being enough powerful. Based on Copeland' criteria for effective procedures, we define what a \emph{physically plausible} computation environment is. We construct two \emph{physically plausible} and \emph{enough powerful} computation environments: 1- the Turing computation environment, denoted by ETE_T, and 2- a persistently evolutionary computation environment, denoted by EeE_e, which persistently evolve in the course of executing the computations. We prove that the equality of complexity classes P\mathrm{P} and NP\mathrm{NP} in the computation environment EeE_e conflicts with the \underline{free will} of the computist. We provide an axiomatic system T\mathcal{T} for Turing computability and prove that ignoring just one of the axiom of T\mathcal{T}, it would not be possible to derive P=NP\mathrm{P=NP} from the rest of axioms. We prove that the computist who lives inside the environment ETE_T, can never be confident that whether he lives in a static environment or a persistently evolutionary one.Comment: 33 pages, interactive computation, P vs N

    A Hypercomputation in Brouwer's Constructivism

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    In contrast to other constructivist schools, for Brouwer, the notion of "constructive object" is not restricted to be presented as `words' in some finite alphabet of symbols, and choice sequences which are non-predetermined and unfinished objects are legitimate constructive objects. In this way, Brouwer's constructivism goes beyond Turing computability. Further, in 1999, the term hypercomputation was introduced by J. Copeland. Hypercomputation refers to models of computation which go beyond Church-Turing thesis. In this paper, we propose a hypercomputation called persistently evolutionary Turing machines based on Brouwer's notion of being constructive.Comment: This paper has been withdrawn by the author due to crucial errors in theorems 4.6 and 5.2 and definition 4.

    A Computational Model and Convergence Theorem for Rumor Dissemination in Social Networks

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    The spread of rumors, which are known as unverified statements of uncertain origin, may cause tremendous number of social problems. If it would be possible to identify factors affecting spreading a rumor (such as agents' desires, trust network, etc.), then this could be used to slowdown or stop its spreading. A computational model that includes rumor features and the way a rumor is spread among society's members, based on their desires, is therefore needed. Our research is centering on the relation between the homogeneity of the society and rumor convergence in it and result shows that the homogeneity of the society is a necessary condition for convergence of the spreading rumor.Comment: 29 pages, 7 figure

    Study of behaviour of Biomechanical System in indented Articular Cartilage on a cellular level

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    The study of biomechanical systems is of great interest to researches due to diverse applications in the medical sector. This study focuses on design and implementation of a mechanical device, a novel dual axis construct simulator (DACS) for in vitro studies on immortalised chondrocytes. DACS will help with experimental measurements of mechanical properties of Articular Cartilage (AC) on a cellular level and the relationship among cellular, pericellular and extracellular deformation in AC. Details provided in this research mainly focuses on software and hardware development processes and challenges involved. There will a brief introduction about biomechanical behaviour of the cartilage and DACS impact on future studies. This will be followed by description of LCMPilot, an experimental software and challenges involved to develop and control DACS in an automated setup
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