30,079 research outputs found

    Design and Implementation of an RNS-based 2D DWT Processor

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    Dispersal and noise: Various modes of synchrony in\ud ecological oscillators

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    We use the theory of noise-induced phase synchronization to analyze the effects of dispersal on the synchronization of a pair of predator-prey systems within a fluctuating environment (Moran effect). Assuming that each isolated local population acts as a limit cycle oscillator in the deterministic limit, we use phase reduction and averaging methods to derive a Fokker–Planck equation describing the evolution of the probability density for pairwise phase differences between the oscillators. In the case of common environmental noise, the oscillators ultimately synchronize. However the approach to synchrony depends on whether or not dispersal in the absence of noise supports any stable asynchronous states. We also show how the combination of correlated (shared) and uncorrelated (unshared) noise with dispersal can lead to a multistable\ud steady-state probability density

    Effects of demographic noise on the synchronization of a metapopulation in a fluctuating environment

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    We use the theory of noise-induced phase synchronization to analyze the effects of demographic noise on the synchronization of a metapopulation of predator-prey systems within a fluctuating environment (Moran effect). Treating each local predator–prey population as a stochastic urn model, we derive a Langevin equation for the stochastic dynamics of the metapopulation. Assuming each local population acts as a limit cycle oscillator in the deterministic limit, we use phase reduction and averaging methods to derive the steady state probability density for pairwise phase differences between oscillators, which is then used to determine the degree of synchronization of\ud the metapopulation

    Embracing Imperfection: Contemporary Fashion Communication and Consumer Well-Being

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    Purpose Fashion advertising as a contemporary ideological form has the power to deliver semiotic messages, which frames individuals' perception. Promoting perfection in consumer culture has resulted in the creation of unrealistic self-image and negative effects that led to psychological illnesses and pathological behaviours. The purpose of this paper is to investigate the ideology behind the contemporary fashion advertising that embraces imperfection and is linked to consumer subjective well-being. Design/methodology/approach Nine fashion ads were selected based on the WGSN consumer report Embracing Imperfection. A sample of images was analysed applying semiotic analysis combined with the criteria of content analysis. Findings The results supported the notion that some contemporary fashion communication brands are challenging the conventional idea of perfection. Five themes were identified as the characteristics that bridged the visual surface of advertising with its hidden ideologies of imperfection. By supporting “anonymity”, fashion brand communication is against excessive self-focus and helps reducing anxiety due to being imperfect. By promoting “rawness”, it encourages authenticity and uniqueness. “Banality” rejects materialism and promotes the beauty of the boring day. “Ugliness” advocates for removal of the single standards and celebrate individual differences, and “spontaneity” is interchangeable for humanity, freedom, openness and acceptance of self. Originality/value This study is among the few attempts to conduct semiotic analysis of fashion advertising images aiming to identify the visual components and ideologies that could potentially be linked to subjective well-being in fashion communication

    Cusp-scaling behavior in fractal dimension of chaotic scattering

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    A topological bifurcation in chaotic scattering is characterized by a sudden change in the topology of the infinite set of unstable periodic orbits embedded in the underlying chaotic invariant set. We uncover a scaling law for the fractal dimension of the chaotic set for such a bifurcation. Our analysis and numerical computations in both two- and three-degrees-of-freedom systems suggest a striking feature associated with these subtle bifurcations: the dimension typically exhibits a sharp, cusplike local minimum at the bifurcation.Comment: 4 pages, 4 figures, Revte

    Dissipative chaotic scattering

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    We show that weak dissipation, typical in realistic situations, can have a metamorphic consequence on nonhyperbolic chaotic scattering in the sense that the physically important particle-decay law is altered, no matter how small the amount of dissipation. As a result, the previous conclusion about the unity of the fractal dimension of the set of singularities in scattering functions, a major claim about nonhyperbolic chaotic scattering, may not be observable.Comment: 4 pages, 2 figures, revte

    A compressible near-wall turbulence model for boundary layer calculations

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    A compressible near-wall two-equation model is derived by relaxing the assumption of dynamical field similarity between compressible and incompressible flows. This requires justifications for extending the incompressible models to compressible flows and the formulation of the turbulent kinetic energy equation in a form similar to its incompressible counterpart. As a result, the compressible dissipation function has to be split into a solenoidal part, which is not sensitive to changes of compressibility indicators, and a dilational part, which is directly affected by these changes. This approach isolates terms with explicit dependence on compressibility so that they can be modeled accordingly. An equation that governs the transport of the solenoidal dissipation rate with additional terms that are explicitly dependent on the compressibility effects is derived similarly. A model with an explicit dependence on the turbulent Mach number is proposed for the dilational dissipation rate. Thus formulated, all near-wall incompressible flow models could be expressed in terms of the solenoidal dissipation rate and straight-forwardly extended to compressible flows. Therefore, the incompressible equations are recovered correctly in the limit of constant density. The two-equation model and the assumption of constant turbulent Prandtl number are used to calculate compressible boundary layers on a flat plate with different wall thermal boundary conditions and free-stream Mach numbers. The calculated results, including the near-wall distributions of turbulence statistics and their limiting behavior, are in good agreement with measurements. In particular, the near-wall asymptotic properties are found to be consistent with incompressible behavior; thus suggesting that turbulent flows in the viscous sublayer are not much affected by compressibility effects
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