599 research outputs found

    Interacting crumpled manifolds

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    In this article we study the effect of a delta-interaction on a polymerized membrane of arbitrary internal dimension D. Depending on the dimensionality of membrane and embedding space, different physical scenarios are observed. We emphasize on the difference of polymers from membranes. For the latter, non-trivial contributions appear at the 2-loop level. We also exploit a ``massive scheme'' inspired by calculations in fixed dimensions for scalar field theories. Despite the fact that these calculations are only amenable numerically, we found that in the limit of D to 2 each diagram can be evaluated analytically. This property extends in fact to any order in perturbation theory, allowing for a summation of all orders. This is a novel and quite surprising result. Finally, an attempt to go beyond D=2 is presented. Applications to the case of self-avoiding membranes are mentioned

    How long does it take to pull an ideal polymer into a small hole?

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    We present scaling estimates for characteristic times τlin\tau_{\rm lin} and τbr\tau_{\rm br} of pulling ideal linear and randomly branched polymers of NN monomers into a small hole by a force ff. We show that the absorbtion process develops as sequential straightening of folds of the initial polymer configuration. By estimating the typical size of the fold involved into the motion, we arrive at the following predictions: τlin(N)N3/2/f\tau_{\rm lin}(N) \sim N^{3/2}/f and τbr(N)N5/4/f\tau_{\rm br}(N) \sim N^{5/4}/f, and we also confirm them by the molecular dynamics experiment.Comment: 4 pages, 3 figure

    Wandering of a contact line at thermal equilibrium

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    We reconsider the problem of the solid-liquid-vapour contact-line on a disordered substrate, in the collective pinning regime. We go beyond scaling arguments and perform an analytic computation, through the replica variational method, of the fluctuations of the line. We show how gravity effects must be included for a proper quantitative comparison with available experimental data of the wetting of liquid helium on a caesium substrate. The theoretical result is in good agreement with experimental findings for this case.Comment: 24 laTex pages with 5 EPS figures included. submitted to Phys. Rev

    Praise or blame? Affective influences on attributions for achievement

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    Three experiments showed that mood influences achievement attributions and that cognitive processes underlie these effects. In Experiment 1, happy Ss made more internal and stable attributions for success than failure in typical 'life dilemmas'. In Experiment 2, attributions for real-life exam performance were more internal and stable in a happy than in a sad mood. Dysphoric moods resulted in self-critical rather than self-enhancing attributions, contrary to motivational theories, but consistent with cognitive models and the clinical literature on depression. In Experiment 3 this pattern was repeated with direct self vs. other comparisons, and for self-efficacy judgments. The results are interpreted as supporting cognitive rather than motivational theories of attribution biases. The implications of the results for clinical research, and contemporary affect-cognition theories are considered

    Localization in simple multiparticle catalytic absorption model

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    We consider the phase transition in the system of n simultaneously developing random walks on the halfline x>=0. All walks are independent on each others in all points except the origin x=0, where the point well is located. The well depth depends on the number of particles simultaneously staying at x=0. We consider the limit n>>1 and show that if the depth growth faster than 3/2 n ln(n) with n, then all random walks become localized simultaneously at the origin. In conclusion we discuss the connection of that problem with the phase transition in the copolymer chain with quenched random sequence of monomers considered in the frameworks of replica approach.Comment: 17 pages in LaTeX, 5 PostScript figures; submitted to J.Phys.(A): Math. Ge

    On the reciprocal interaction between believing and feeling: an adaptive agent modelling perspective

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    An agent’s beliefs usually depend on informational or cognitive factors such as observation or received communication or reasoning, but also affective factors may play a role. In this paper, by adopting neurological theories on the role of emotions and feelings, an agent model is introduced incorporating the interaction between cognitive and affective factors in believing. The model describes how the strength of a belief may not only depend on information obtained, but also on the emotional responses on the belief. For feeling emotions a recursive body loop between preparations for emotional responses and feelings is assumed. The model introduces a second feedback loop for the interaction between feeling and belief. The strength of a belief and of the feeling both result from the converging dynamic pattern modelled by the combination of the two loops. For some specific cases it is described, for example, how for certain personal characteristics an optimistic world view is generated in the agent’s beliefs, or, for other characteristics, a pessimistic world view. Moreover, the paper shows how such affective effects on beliefs can emerge and become stronger over time due to experiences obtained. It is shown how based on Hebbian learning a connection from feeling to belief can develop. As these connections affect the strenghts of future beliefs, in this way an effect of judgment ‘by experience built up in the past’ or ‘by gut feeling’ can be obtained. Some example simulation results and a mathematical analysis of the equilibria are presented

    In Search for the Rationality of Moods

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    What it is about mood, as a specific type of affect, that makes it not easily amenable to standard models of rationality? It is commonly assumed that the cognitive rationality of an affective state is somehow depended upon how that state is related to what the state is about, its so called intentional object; but, given that moods do not seem to bear an intentional relation to an object, it is hard to see how they can be in the offing for rational assessment. In the first part of the paper I outline three ways of attributing intentionality to moods, raising for each one of them a series of problems, thus casting doubt on the viability of an intentionalist grounding for the rationality of moods. I then move to an examination of the view of moods as background feelings, which are intimately related to how we perceive the world; however, in my view, that approach fails to provide standards of assessment that would permit appraising the mood itself as rational or irrational. Finally, I look at an account of moods as mechanisms whose function is to monitor the balance between environmental demands and one’s physical or psychological resources. That is a promising way to proceed in our exploration of mood states; it faces though some formidable phenomenological challenges. All in all, defending the rationality of moods calls for a rethinking of the assumptions that are prevalent in the current literature over the representational dimension of affective states

    Collective narcissism as a framework for understanding populism

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    Research on national collective narcissism, the belief and resentment that a nation's exceptionality is not sufficiently recognized by others, provides a theoretical framework for understanding the psychological motivations behind the support for right-wing populism. It bridges the findings regarding the economic and sociocultural conditions implicated in the rise of right-wing populism and the findings regarding leadership processes necessary for it to find its political expression. The conditions are interpreted as producing violations to established expectations regarding self-importance via the gradual repeal of the traditional criteria by which members of hegemonic groups evaluated their self-worth. Populist leaders propagate a social identity organized around the collective narcissistic resentment, enhance it, and propose external explanations for frustration of self and in-group-importance. This garners them a committed followership. Research on collective narcissism indicates that distress resulting from violated expectations regarding self-importance stands behind collective narcissism and its narrow vision of “true” national identity (the people), rejection and hostility toward stigmatized in-group members and out-groups as well as the association between collective narcissism and conspiratorial thinking

    Risk perception and vulnerability of value: a study in the context of commercial property sector

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    © 2016 The Author(s). Published by Vilnius Gediminas Technical University (VGTU) Press, and Taylor & Francis. The research was developed linking the impact of flood risk on utility, desirability and marketability related to vulnerability of commercial property value. Likert style questionnaire survey was conducted to obtain data from flood affected and un-affected respondents across different designated flood risk zones on key business and perception variables among two groups of business property holders in England. The responses were analysed through a spatial vulnerability model to illustrate the distribution of the vulnerability of value of properties among flood plain business holders on a GIS platform. Majority of respondents perceived that utility of properties may be hampered by flooding and subsequently have an impact on value for property at risk. Those with flood experience gave greater weight to their specific business needs such as the prime location and expected income level than those without flood experience. The implication of the study lies in understanding that flood risk perceptions can shape actions of people at risk towards future increase in resilience having strategic impact on value of property saleability in the future
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