55,859 research outputs found

    Beyond and Behind Platforms and Algorithms: Exploring the Lived Experiences of Gig Workers

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    While the literature on gig work is expanding rapidly, many are the issues that need to be answered in order to fully understand the lived experiences of gig workers and illuminate the dynamics of gig work. Despite it is widely recognized that gig workers constitute an heterogenous workforce, for instance, seminal works have focused on finding similarities among gig workers across platforms, while the mechanisms behind different gig workers’ behaviors and perceptions are still widely obscure. Moreover, most of the literature focuses on what gig workers do individually on platforms, but not – or only cursorily – on how these workers manage the interplay between their online and offline activities. Specifically, comprehending how the online dimensions of work blur or integrate with offline aspects of gig workers’ lives – such as family condition or family needs, the presence of alternative, offline jobs, the cultural context of the community and country of origin – is of significant importance. This symposium addresses these issues by examining what happens behind and beyond platforms, and by presenting four papers looking at different gig workers’ experiences and different forms of interplay between online and offline aspects of gig work. A Multi-National Ethnography of Ride-Hailing in the Global South Author: Lindsey Cameron; The Wharton School, U. of Pennsylvania Author: Bobbi Thomason; Pepperdine Graziadio Business School Understanding African Digital Platform Workers’ Behaviours through the Lens of Omoluwabi Ethos Author: Ayomikun Idowu; U. of Sussex Business School Gig workers and Wellbeing: How is Algorithmic Work related to Work-Life Balance? Author: Francesca Bellesia; Dep. of Sciences and Methods for Engineering, U. of Modena and Reggio Emilia Author: Fabiola Bertolotti; U. of Modena and Reggio Emilia Author: Elisa Mattarelli; San Jose State U. Gig work in organizations: Trends and perspectives from Human Resource Management professionals Author: Ksenia Keplinger; Max Planck Institute for Intelligent Systems Author: Aizhan Tursunbayeva; Parthenope U. of Naples Author: Vindhya Singh; Max Planck Institute for Intelligent Systems Author: Stefano Di Lauro; U. Mercatoru

    Sex trafficking of girls and women : Evidence from Anantapur district, Andhra Pradesh

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    A crucial gap in the trafficking literature from India is the dearth of primary data and micro studies that could be used for vulnerability mapping of the source areas and addressing the identified risk factors. The present paper is a small attempt to contribute to plugging the gap in the context of Andhra Pradesh, identified as a hot spot in the trafficking literature. This paper is based on case studies of 78 women who had been trafficked from their places of origin in Anantapur district in Andhra Pradesh to metropolitan cities across India and who have since returned to their homes. The paper attempted to identify the individual and family circumstances that contribute to the causes of trafficking, to highlight in particular the gendered vulnerabilities that set these women up for trafficking, and to capture the process of the trafficking experience. The findings of the study are located in the dynamic interplay of the social structural context and specificities of the district that contribute to causes of trafficking and the individual circumstances and agency of the women. The case studies reported in this paper are a pointer to the compelling urgency of interventions that will go beyond the forced / voluntary divide in trafficking and sex work.Andhra Pradesh, India, trafficking

    A Dynamic Subfilter-scale Stress Model for Large Eddy Simulations Based on Physical Flow Scales

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    We propose a new definition of the length scale in an eddy-viscosity model for large-eddy simulations (LES). This formulation extends and generalizes a previous proposal [Piomelli, Rouhi and Geurts, Proc. ETMM10, 2014], in which the LES length scale was expressed in terms of the integral length-scale of turbulence determined by the flow characteristics and explicitly decoupled from the simulation grid; this approach was named Integral Length-Scale Approximation (ILSA). As in the original ILSA, the model coefficient was determined by the user, and required to maintain a desired contribution of the unresolved, subfilter scales (SFS) to the global transport. We propose a local formulation (local ILSA) in which the model coefficient is local in space, allowing a precise control over SFS activity as a function of location. This new formulation preserves the properties of the global model; application to channel flow and backward-facing step verifies its features and accuracy

    Large-eddy simulation of a separated flow with a sub-filter scale model based on the integral length-scale

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    A new sub-filter scale model for large-eddy simulations, which uses a length-scale proportional to the integral scale of the turbulence instead of the grid resolution to parametrize the modelled stresses, will be assessed in the prediction of the flow of a boundary-layer over a rough surface, which includes separation and reattachment

    Near Wall PIV-Measurements on the Windward Slope of a Hill

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    The turbulent flow over periodic hills was measured near to the wall, using planar Particle-Image-Velocimetry (PIV) at high spatial resolution. Our focus is on the near wall turbulence structure on the windward slope of the hill. For large-eddy simulation (LES) we suspect that, if this was not predicted accurately, it affects the prediction of the velocity profiles over the hill crest which in turn will affect the recirculation length downstream of the hill. Regarding the time averaged velocities, we were able to resolve the linear viscous region of the boundary layer. The velocity distribution and also the Reynolds stress does not comply with the law of the wall as it is valid for a turbulent boundary layer at equilibrium

    Energy dissipation and flux laws for unsteady turbulence

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    Direct Numerical Simulations of spatially periodic unsteady turbulence show that the high Reynolds number scalings of the instantaneous energy dissipation rate and interscale energy flux at intermediate wavenumbers are qualitatively different from the well-known u(t)3/L(t)u'(t)^{3}/L(t) cornerstone scalings of equilibrium turbulence where u(t)u'(t) and L(t)L(t) are time-dependent rms velocity and integral length-scales. Instead, they both scale as U0L0u(t)2/L(t)2U_{0}L_{0}\:u'(t)^2/L(t)^2 where L0L_0 and U0U_0 are length and velocity scales characterizing initial/overall unsteady turbulence conditions

    Direct numerical simulation of turbulent Couette-Poiseuille flow with zero skin friction

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    The near-wall scaling of mean velocity U(y) is addressed for the case of zero skin friction on one wall of a fully turbulent channel flow. The present DNS results can be added to the evidence in support of the conjecture that U is proportional to √yw in the region just above the wall at which the mean shear dU/dy = 0

    Real-space Manifestations of Bottlenecks in Turbulence Spectra

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    An energy-spectrum bottleneck, a bump in the turbulence spectrum between the inertial and dissipation ranges, is shown to occur in the non-turbulent, one-dimensional, hyperviscous Burgers equation and found to be the Fourier-space signature of oscillations in the real-space velocity, which are explained by boundary-layer-expansion techniques. Pseudospectral simulations are used to show that such oscillations occur in velocity correlation functions in one- and three-dimensional hyperviscous hydrodynamical equations that display genuine turbulence

    Braid Entropy of Faraday Waves driven 2D Turbulence

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    We report new experimental results that use tools from braid theory to characterize two-dimensional turbulent flows driven by Faraday waves. The average topological length of the material fluid lines is found to grow exponentially with time. It allows us to compute the braid’s topological entropy SBraid. We show that SBraid increases as the square root of the turbulence kinetic energy E ~ u^2, where u^2 is the horizontal velocity variance . At long times, the PDFs of Lbraid are positively skewed and present strong exponential tails

    Mean flow generation by Görtler Vortices in a rotating annulus with librating side walls

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    Longitudinal libration of the cylinder side walls of a rotating annulus in the supercritical regime induces a centrifugally unstable Stokes boundary layer which generates Görtler vortices only in a portion of a libration cycle. We show for the first time that these vortices propagate into the fluid bulk and generate an azimuthal mean flow which is retrograde (prograde) over the outer (inner) cylinder side wall. Direct numerical simulations (DNS) are carried out and Reynolds-averaged equations and kinetic energy budget of mean and fluctuating flow are used as diagnostic equations to discuss the generation mechanism and scaling behavior of the azimuthal mean flow in the fluid bulk
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