9,588,554 research outputs found

    Chance, Choice, and Consciousness: The Role of Mind in the Quantum Brain

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    Contemporary quantum mechanical description of nature involves two processes. The first is a dynamical process governed by the equations of local quantum field theory. This process is local and deterministic, but it generates a structure that is not compatible with observed reality. A second process is therefore invoked. This second process somehow analyzes the structure generated by the first process into a collection of possible observable realities, and selects one of these as the actually appearing reality. This selection process is not well understood. It is necessarily nonlocal and, according to orthodox thinking, is governed by an irreducible element of chance. The occurrence of this irreducible element of chance means that the theory is not naturalistic: the dynamics is controlled in part by something that is not part of the physical universe. The present work describes a quantum mechanical model of brain dynamics in which the quantum selection process is a causal process governed not by pure chance but rather by a mathematically specified nonlocal physical process identifiable as the conscious process.Comment: 27 pages, no figures, latexed, uses math_macros.tex that can be found on Archive, full postscript available from http://theor1.lbl.gov/www/theorygroup/papers/37944.p

    On Practical Verification of Processes

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    The integration of a formal process theory with a practically usable notation is not straightforward, but it is necessary for practical verification of process specifications. Given such an intermediate language, a verification process that gives useful feedback is not trivial either: Model checkers are not powerful enough to deal with object models, and theorem provers provide insu#cient feedback and are not certain to find a proof

    Implementation of critical success factors in construction research and development process

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    Construction research and development (R&D) process has a number of issues that affect its success. These issues imply that Critical Success Factors (CSFs) of construction R&D process are not properly addressed. Not knowing CSFs could lead to not implementing them and not paying proper attention for them. The study investigates CSFs of construction R&D process and their implementation/consideration during the R&D process. A comprehensive literature review was used first to develop construction R&D process. CSFs and their implementation/consideration were evaluated by a questionnaire survey. Construction R&D process was derived with four phases namely Initiation, Conceptualizing, Development and Launch and Management activities that support coordination and resourcing of R&D process. Study revealed that, as a whole there is a gap between the importance of success factors against their implementation/consideration as majority of CSFs are not properly implemented compared to the importance attached to them. Keywords: Construction R&D process, Critical success factors, Implementation, Consideratio

    Poisson splitting by factors

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    Given a homogeneous Poisson process on Rd{\mathbb{R}}^d with intensity λ\lambda, we prove that it is possible to partition the points into two sets, as a deterministic function of the process, and in an isometry-equivariant way, so that each set of points forms a homogeneous Poisson process, with any given pair of intensities summing to λ\lambda. In particular, this answers a question of Ball [Electron. Commun. Probab. 10 (2005) 60--69], who proved that in d=1d=1, the Poisson points may be similarly partitioned (via a translation-equivariant function) so that one set forms a Poisson process of lower intensity, and asked whether the same is possible for all dd. We do not know whether it is possible similarly to add points (again chosen as a deterministic function of a Poisson process) to obtain a Poisson process of higher intensity, but we prove that this is not possible under an additional finitariness condition.Comment: Published in at http://dx.doi.org/10.1214/11-AOP651 the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org

    Limiting conditional distributions for birth-death processes

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    In a recent paper one of us identified all of the quasi-stationary distributions for a non-explosive, evanescent birth-death process for which absorption is certain, and established conditions for the existence of the corresponding limiting conditional distributions. Our purpose is to extend these results in a number of directions. We shall consider separately two cases depending on whether or not the process is evanescent. In the former case we shall relax the condition that absorption is certain. Furthermore, we shall allow for the possibility that the minimal process might be explosive, so that the transition rates alone will not necessarily determine the birth-death process uniquely. Although we shall be concerned mainly with the minimal process, our most general results hold for any birth-death process whose transition probabilities satisfy both the backward and the forward Kolmogorov differential equations

    Complete convergence theorem for a two level contact process

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    We study a two-level contact process. We think of fleas living on a species of animals. The animals are a supercritical contact process in Zd\mathbb{Z}^d. The contact process acts as the random environment for the fleas. The fleas do not affect the animals, give birth at rate Ό\mu when they are living on a host animal, and die at rate Ύ\delta when they do not have a host animal. The main result is that if the contact process is supercritical and the fleas survive with a positive probability then the complete convergence theorem holds. This is done using a block construction, so as a corollary we conclude that the fleas die out at their critical value

    A criterion for separating process calculi

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    We introduce a new criterion, replacement freeness, to discern the relative expressiveness of process calculi. Intuitively, a calculus is strongly replacement free if replacing, within an enclosing context, a process that cannot perform any visible action by an arbitrary process never inhibits the capability of the resulting process to perform a visible action. We prove that there exists no compositional and interaction sensitive encoding of a not strongly replacement free calculus into any strongly replacement free one. We then define a weaker version of replacement freeness, by only considering replacement of closed processes, and prove that, if we additionally require the encoding to preserve name independence, it is not even possible to encode a non replacement free calculus into a weakly replacement free one. As a consequence of our encodability results, we get that many calculi equipped with priority are not replacement free and hence are not encodable into mainstream calculi like CCS and pi-calculus, that instead are strongly replacement free. We also prove that variants of pi-calculus with match among names, pattern matching or polyadic synchronization are only weakly replacement free, hence they are separated both from process calculi with priority and from mainstream calculi.Comment: In Proceedings EXPRESS'10, arXiv:1011.601
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