650 research outputs found

    Creators, Audiences, and New Media: Creativity in an Interactive Environment

    Get PDF
    Composition and media scholars have in the past examined the participants and steps in the creative process as distinct roles and actions, with a separation between creators and audiences, including gatekeeping audiences (such as editors and publishers). The act of creation was viewed as taking place in isolation. The media emphasis on traditional genres such as print books has limited the examination of the distribution of these works. New media scholarship explores the ways media creation software and online distribution can complicate creativity and provide new venues for distribution. In this thesis, I claim that the new media environment has changed the traditional creator and audience roles, with boundaries being crossed regularly. Creators may be inspired by the ideas of a particular audience, the distribution of their works might bypass gatekeepers, and the audience may use these works in their own creations. The Internet allows us to observe and examine these changes both in real-time and after the fact. Chapter One, "Creator/Audience Roles and New Media Interactivity," presents a framework for discussion that incorporates several existing definitions of audience roles, with a look at more recent perspectives on how audiences dynamically interact with creators. In the process, the conceptual limits of bounded roles such as "publics" and "fandoms" will be examined, and the complicating factors of new media interactivity will be established. Chapter Two, "Permeable Boundaries: The Shifting Roles of Creation, Reception, and Utilization," examines how audience actions allow readers and creators to cross these conceptual boundaries, sparking creative impulses. Attention is also paid to the different kinds of value for creativity and interaction established by fandoms. Chapter Three, "Creativity, Information Technology, and New Media," looks at the ways in which the availability and relatively easy use of digital tools and the Internet have allowed more people to perform and share their creative acts. This chapter will include case studies that illustrate how online creators deal with the difference between traditional and new media versions of success and integrate digital tools and distribution to find creative fulfillment; the chapter will also examine the benefits and problems inherent in a high level of creator-audience interaction, such as the successful use of social media to create new opportunities for releasing media works while opening oneself to criticism from unintended audiences

    Geometric Correction for a Spherical mirror projection on a Nonplanar Surface

    Get PDF
    This paper discusses an approach for removing distortion from an image projected on a non-planar surface. With a single projector setup in a spherical mirror projection system, it becomes possible to preserve image features. The approach takes advantage of the configuration of the surface, specifically, the geodesic dome in this project. The configuration acts as a mold so that a warp mesh can be designed to match the surface configuration. Points in an image are then mapped to their corresponding point on the destination multi-planar surface represented by the mesh. The removal of distortion brings us a step closer to automating processes like this and paves a way for experimenting with applications in an immersive environment

    Numerosity and density judgments: Biases for area but not for volume

    No full text
    International audienceHuman observers can rapidly judge the number of items in a scene. This ability is underpinned by specific mechanisms encoding number or density. We investigated whether judgments of number and density are biased by a change in volume, as they are by a change in area. Stimuli were constructed using nonoverlapping black and white luminance-defined dots. An eight-mirror Wheatstone stereoscope was used to present the dots as though in a volume. Using a temporal two-alternative forced-choice (2AFC) task and the Method of Constant Stimuli (MOCS), we measured the precision and bias (PSE shift) of numerosity and density judgments, separately, for stimuli differing in area or volume. For two-dimensional (2-D) stimuli, consistent with previous literature, perceived density was biased as area increased. However, perceived number was not. For three-dimensional (3-D) stimuli, despite a vivid impression of the dots filling a cylindrical volume, there was no bias in perceived density or number as volume increased. A control experiment showed that all of our observers could easily perceive disparity in our stimuli. Our findings reveal that number and density judgments that are biased by area are not similarly biased by volume changes

    Angular Momentum Transfer and Lack of Fragmentation in Self-Gravitating Accretion Flows

    Full text link
    Rapid inflows associated with early galaxy formation lead to the accumulation of self-gravitating gas in the centers of proto-galaxies. Such gas accumulations are prone to non-axisymmetric instabilities, as in the well-known Maclaurin sequence of rotating ellipsoids, which are accompanied by a catastrophic loss of angular momentum (J). Self-gravitating gas is also intuitively associated with star formation. However, recent simulations of the infall process display highly turbulent continuous flows. We propose that J-transfer, which enables the inflow, also suppresses fragmentation. Inefficient J loss by the gas leads to decay of turbulence, triggering global instabilities and renewed turbulence driving. Flow regulated in this way is stable against fragmentation, whilst staying close to the instability threshold for bar formation -- thick self-gravitating disks are prone to global instabilities before they become unstable locally. On smaller scales, the fraction of gravitationally unstable matter swept up by shocks in such a flow is a small and decreasing function of the Mach number. We conclude counterintuitively that gas able to cool down to a small fraction of its virial temperature will not fragment as it collapses. This provides a venue for supermassive black holes to form via direct infall, without the intermediary stage of forming a star cluster. Some black holes could have formed or grown in massive halos at low redshifts. Thus the fragmentation is intimately related to J redistribution within the system: it is less dependent on the molecular and metal cooling but is conditioned by the ability of the flow to develop virial, supersonic turbulence.Comment: 5 pp., 1 figures, to be published by the Astrophysical Journal Letters. Minor corrections following the referee repor

    New parameterization of air-sea exchange coefficients and its impact on intensity prediction under major tropical cyclones

    Get PDF
    Understanding and quantifying air-sea exchanges of enthalpy and momentum fluxes are crucial for the advanced prediction of tropical cyclone (TC) intensity. Here, we present a new parameterization of air-sea fluxes at extreme wind speeds from 40 m s−1 to 75 m s−1, which covers the range of major TCs. Our approach assumes that the TC can reach its maximum potential intensity (MPI) if there are no influences of external forces such as vertical wind shear or other environmental constraints.This method can estimate the ratio of the enthalpy and momentum exchange coefficient (Ck/Cd) under the most intense TCs without direct flux measurements. The estimation showed that Ck/Cd increases with wind speed at extreme winds above 40 m s−1. Two types of surface layer schemes of the Hurricane Weather and Research Forecast (HWRF) were designed based on the wind speed dependency of the Ck/Cd found at high winds: (i) an increase of Ck/Cd based on decreasing Cd (Cd_DC) and (ii) an increase of Ck/Cd based on increasing Ck (Ck_IC). The modified surface layer schemes were compared to the original HWRF scheme (using nearly fixed Cd and Ck at extreme winds; CTRL) through idealized experiments and real-case predictions. The idealized experiments showed that Cd_DC reduced frictional dissipation in the air-sea interface as well as significantly reduced sea surface cooling, making the TC stronger than other schemes. As a result, Cd_DC reduced the mean absolute error and negative bias by 15.0% (21.0%) and 19.1% (32.0%), respectively, for all lead times of Hurricane Irma in 2017 (Typhoon Mangkhut in 2018) compared to CTRL. This result suggests that new parameterization of Ck/Cd with decreasing Cd at high winds can help improve TC intensity prediction, which currently suffers from underestimating the intensity of the strongest TCs

    A Comparison of Network Sampling Designs for a Hidden Population of Drug Users: Random Walk vs. Respondent-Driven Sampling

    Get PDF
    Both random walk and respondent-driven sampling (RDS) exploit social networks and may reduce biases introduced by earlier methods for sampling from hidden populations. Although RDS has become much more widely used by social researchers than random walk (RW), there has been little discussion of the tradeoffs in choosing RDS over RW. This paper compares experiences of implementing RW and RDS to recruit drug users to a network-based study in Houston, Texas. Both recruitment methods were implemented over comparable periods of time, with the same population, by the same research staff. RDS methods recruited more participants with less strain on staff. However, participants recruited through RW were more forthcoming than RDS participants in helping to recruit members of their social networks. Findings indicate that, dependent upon study goals, researchers' choice of design may influence participant recruitment, participant commitment, and impact on staff, factors that may in turn affect overall study success

    Pandemic Influenza as 21st Century Urban Public Health Crisis

    Get PDF
    Responses of Mexico City and New York City in spring 2009 illustrate the importance of advance planning

    Dark Matter Halos and Evolution of Bars in Disk Galaxies: Varying Gas Fraction and Gas Spatial Resolution

    Get PDF
    We conduct numerical experiments by evolving gaseous/stellar disks embedded in live dark matter halos aiming at quantifying the effect of gas spatial resolution and gas content on the bar evolution. Model sequences have been constructed using different resolution, and gas fraction has been varied along each sequence within fgas=0%-50%, keeping the disk and halo properties unchanged. We find that the spatial resolution becomes important with an increase in `fgas'. For the higher resolution model sequences, we observe a bimodal behavior in the bar evolution with respect to the gas fraction, especially during the secular phase of this evolution. The switch from the gas-poor to gas-rich behavior is abrupt and depends on the resolution used. The diverging evolution has been observed in nearly all basic parameters characterizing bars, such as the bar strength, central mass concentration, vertical buckling amplitude, size, etc. We find that the presence of the gas component severely limits the bar growth and affects its pattern speed evolution. Gas-poor models display rapidly decelerating bars, while gas-rich models exhibit bars with constant or even slowly accelerating tumbling. The gas-rich models have bar corotation (CR) radii within the disk at all times, in constrast with gas-poor and purely stellar disks. The CR-to-bar size ratio is less than 2 for gas rich-models. We have confirmed that the disk angular momentum within the CR remains unchanged in the gas-poor models, as long as the CR stays within the disk, but experiences a sharp drop before leveling off in the gas-rich models. Finally, we discuss a number of observed correlations between various parameters of simulated bars, e.g., bar sizes and gas fractions, bar strength and buckling amplitude, bar strength and its size, etc.Comment: 13 pages, 13 figures, to be published by the Astrophysical Journal; minor changes following the referee repor
    corecore