4,100 research outputs found

    Source Reading for Contentious Gatherings in Nineteenth-Century British Newspapers

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    http://deepblue.lib.umich.edu/bitstream/2027.42/50960/1/186.pd

    How Damage Diversification Can Reduce Systemic Risk

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    We consider the problem of risk diversification in complex networks. Nodes represent e.g. financial actors, whereas weighted links represent e.g. financial obligations (credits/debts). Each node has a risk to fail because of losses resulting from defaulting neighbors, which may lead to large failure cascades. Classical risk diversification strategies usually neglect network effects and therefore suggest that risk can be reduced if possible losses (i.e., exposures) are split among many neighbors (exposure diversification, ED). But from a complex networks perspective diversification implies higher connectivity of the system as a whole which can also lead to increasing failure risk of a node. To cope with this, we propose a different strategy (damage diversification, DD), i.e. the diversification of losses that are imposed on neighboring nodes as opposed to losses incurred by the node itself. Here, we quantify the potential of DD to reduce systemic risk in comparison to ED. For this, we develop a branching process approximation that we generalize to weighted networks with (almost) arbitrary degree and weight distributions. This allows us to identify systemically relevant nodes in a network even if their directed weights differ strongly. On the macro level, we provide an analytical expression for the average cascade size, to quantify systemic risk. Furthermore, on the meso level we calculate failure probabilities of nodes conditional on their system relevance

    Time dependence of the survival probability of an opinion in a closed community

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    The time dependence of the survival probability of an opinion in a closed community has been investigated in accordance with social temperature by using the Kawasaki-exchange dynamics based on previous study in Ref. [1]. It is shown that the survival probability of opinion decays with stretched exponential law consistent with previous static model. However, the crossover regime in the decay of the survival probability has been observed in this dynamic model unlike previous model. The decay characteristics of both two regimes obey to stretched exponential.Comment: Revised version of the paper (9 page, 5 Figures). Submitted to Int. J. Mod. Phys.

    Evoking the Ineffable: The Phenomenology of Extreme Sports

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    We are witnessing an unprecedented interest in and engagement with extreme sport activities. Extreme sports are unique in that they involve physical prowess as well as a particular attitude towards the world and the self. We have scant understanding of the experience of participants who engage in extreme activities such as BASE jumping, big wave surfing, extreme skiing, waterfall kayaking, extreme mountaineering, and solo rope free climbing. The current study investigates the experience of people who engage in extreme sports utilizing a phenomenological approach. The study draws upon interviews with 15 extreme sports participants across three continents to explicate three unique themes: extreme sports as invigorating experience, inadequacy of words, and participants’ experience of transcendence. The findings provide a valuable insight into the experiences of the participants and contribute to our understanding of human volition and the range of human experiences

    Non-equilibrium dynamics of an active colloidal "chucker"

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    We report Monte Carlo simulations of the dynamics of a "chucker": a colloidal particle which emits smaller solute particles from its surface, isotropically and at a constant rate k_c. We find that the diffusion constant of the chucker increases for small k_c, as recently predicted theoretically. At large k_c the chucker diffuses more slowly due to crowding effects. We compare our simulation results to those of a "point particle" Langevin dynamics scheme in which the solute concentration field is calculated analytically, and in which hydrodynamic effects can be included albeit in an approximate way. By simulating the dragging of a chucker, we obtain an estimate of its apparent mobility coefficient which violates the fluctuation-dissipation theorem. We also characterise the probability density profile for a chucker which sediments onto a surface which either repels or absorbs the solute particles, and find that the steady state distributions are very different in the two cases. Our simulations are inspired by the biological example of exopolysaccharide-producing bacteria, as well as by recent experimental, simulation and theoretical work on phoretic colloidal "swimmers".Comment: re-submission after referee's comment

    Extreme sports are good for your health: a phenomenological understanding of fear and anxiety in extreme sport.

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    Extreme sports are traditionally explored from a risk-taking perspective which often assumes that participants do not experience fear. In this article we explore participants' experience of fear associated with participation in extreme sports. An interpretive phenomenological method was used with 15 participants. Four themes emerged: experience of fear, relationship to fear, management of fear, and fear and self-transformation. Participants' experience of extreme sports was revealed in terms of intense fear but this fear was integrated and experienced as a potentially meaningful and constructive event in their lives. The findings have implications for understanding fear as a potentially transformative process

    Statistical mechanics of the international trade network

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    Analyzing real data on international trade covering the time interval 1950-2000, we show that in each year over the analyzed period the network is a typical representative of the ensemble of maximally random weighted networks, whose directed connections (bilateral trade volumes) are only characterized by the product of the trading countries' GDPs. It means that time evolution of this network may be considered as a continuous sequence of equilibrium states, i.e. quasi-static process. This, in turn, allows one to apply the linear response theory to make (and also verify) simple predictions about the network. In particular, we show that bilateral trade fulfills fluctuation-response theorem, which states that the average relative change in import (export) between two countries is a sum of relative changes in their GDPs. Yearly changes in trade volumes prove that the theorem is valid.Comment: 6 pages, 2 figure

    Universal Conductance and Conductivity at Critical Points in Integer Quantum Hall Systems

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    The sample averaged longitudinal two-terminal conductance and the respective Kubo-conductivity are calculated at quantum critical points in the integer quantum Hall regime. In the limit of large system size, both transport quantities are found to be the same within numerical uncertainty in the lowest Landau band, 0.60±0.02e2/h0.60\pm 0.02 e^2/h and 0.58±0.03e2/h0.58\pm 0.03 e^2/h, respectively. In the 2nd lowest Landau band, a critical conductance 0.61±0.03e2/h0.61\pm 0.03 e^2/h is obtained which indeed supports the notion of universality. However, these numbers are significantly at variance with the hitherto commonly believed value 1/2e2/h1/2 e^2/h. We argue that this difference is due to the multifractal structure of critical wavefunctions, a property that should generically show up in the conductance at quantum critical points.Comment: 4 pages, 3 figure
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