494,893 research outputs found

    Full-sky ray-tracing simulation of weak lensing using ELUCID simulations: exploring galaxy intrinsic alignment and cosmic shear correlations

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    The intrinsic alignment of galaxies is an important systematic effect in weak-lensing surveys, which can affect the derived cosmological parameters. One direct way to distinguish different alignment models and quantify their effects on the measurement is to produce mocked weak-lensing surveys. In this work, we use full-sky ray-tracing technique to produce mock images of galaxies from the ELUCID NN-body simulation run with the WMAP9 cosmology. In our model we assume that the shape of central elliptical galaxy follows that of the dark matter halo, and spiral galaxy follows the halo spin. Using the mocked galaxy images, a combination of galaxy intrinsic shape and the gravitational shear, we compare the predicted tomographic shear correlations to the results of KiDS and DLS. It is found that our predictions stay between the KiDS and DLS results. We rule out a model in which the satellite galaxies are radially aligned with the center galaxy, otherwise the shear-correlations on small scales are too high. Most important, we find that although the intrinsic alignment of spiral galaxies is very weak, they induce a positive correlation between the gravitational shear signal and the intrinsic galaxy orientation (GI). This is because the spiral galaxy is tangentially aligned with the nearby large-scale overdensity, contrary to the radial alignment of elliptical galaxy. Our results explain the origin of detected positive GI term from the weak-lensing surveys. We conclude that in future analysis, the GI model must include the dependence on galaxy types in more detail.Comment: 23 pages, 13 figures, published in ApJ. Our mock galaxy catalog is available upon request by email to the author ([email protected], [email protected]

    Prosocial Messaging During the COVID-19 Pandemic: A Longitudinal Examination of Email Advertisements

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    Purpose This study aims to evaluate how brands communicate with consumers through the COVID-19 pandemic and how messaging has shifted over time. The authors identify a typology drawn from extant literature and use it to understand how brands shape consumers’ behavior. Design/methodology/approach Through a mix of interpretive and thematic analysis, the authors examine 858 US email advertisements and how these messages have evolved throughout the pandemic. Findings The authors findings demonstrate brand communication ranges from prosocial to brand messaging and brands employed different strategies at different phases of the pandemic. Specifically, while brands started out emphasizing socially desirable behavior before and directly after a national emergency was declared, COVID-19-related communications shifted to predominantly marketing-related messages later in the pandemic. Originality/value This study provides valuable insight into how brands adjust communication strategies through a prolonged cultural trauma and how these messages relate to authenticity, the triple bottom line and a social (versus branded) focus

    Object categorisation, object naming, and viewpoint-independence in visual remembering: Evidence from young children's drawings of a novel object

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    A simple object-drawing task confirms a three-way association between object categorisation, viewpoint independence, and longer-term visual remembering. Young children (5- to 7-year-olds) drew a familiar object or a novel object, immediately after it had been hidden from view or on the following day. Both objects were shown from a full range of viewpoints or from just two viewpoints, from neither of which would either object normally be drawn after unrestricted viewing. When drawing from short-term memory after restricted viewing, both objects were most likely to be depicted from a seen viewpoint. When drawing from longer-term memory after restricted viewing, the novel object continued to be drawn from a seen viewpoint, but the mug was now most likely to be drawn from a preferred viewpoint from which it had not been seen. Naming the novel object with a novel count noun ("Look at this. This is a dax"), to signal that it belonged to an object category, resulted in it being drawn in the same way as the familiar object. The results concur with other evidence indicating that short-term and longer-term visual remembering are differentially associated with viewpoint-dependent representations of individual objects and viewpoint independent representations of object categories, respectively

    Genre analysis of structured e-mails for corpus profiling.

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    This paper reports on our approach to the analysis of genre recognition using eyetracking. We focused on a collection of different types of email which could represent different datasets, such as, mailing lists for calls for papers, newsletters, etc. We found that genre analysis based on purpose, form and layout features is potentially effective for identifying the characteristics of these datasets and we have highlighted some of the new important features of genres. The results from a pilot study showed a clear effect, with an interaction between the email texts and the visual cues or features perceived and also the strategies employed for the processing of the texts. We found, in our small sample, that readers can determine the purpose and form of genres and that during this process some readers do skim the shape of the e-mails (form)

    FE analysis on tube hydroforming of small diametr ZM21 magnesium alloy tube

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    Tube hydroforming (THF) is one of the plasticity processing methods. Tubular parts, for instance automotive components are expanded by forces such as internal pressure and axial compression in order to deform an objective shape. THF has less restriction on shape and size of workpieces owing to adopting the liquid tool. The demand of a small diameter magnesium alloy tubular parts have been increased for applying small medical and electronic devices. In this study, it was investigated that influence of process conditions such as processing temperature, internal pressure and axial feeding amount on formability of small diameter ZM21 magnesium alloy tube with outer diameter of 2.0mm and thickness of 0.20mm. Furthermore, the processing conditions for improving the formability of material in THF were examined. For prior evaluation of deformation characteristics in the warm THF of small diameter ZM21 magnesium alloy tube, a finite element (FE) simulation was conducted. The FE method (FEM) code was used LS-DYNA 3D for analysis of the FE model of the tube and the dies. The material characteristics were obtained by tensile test and fracture test. From FE analysis results, it was elucidated that effect of the processing temperature, the variable internal pressure and the axial feeding amount on deformation behavior. The formability of ZM21 magnesium alloy tube was improved by processing at 250 C. The difference of deformation characteristic between FE results and experimental results was compared. As the results, the processing condition which could improve the formability of ZM21 tube was clarified using this FE model. The effect of adding the straightening stage in the loading path after the preform on formability was investigated. The thinning of the wall thickness of the tube was inhibited by calibration after the axial feeding
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