1,144 research outputs found

    Visual discomfort and blur

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    Certain visual stimuli, such as striped patterns and filtered noise, have been reported to be uncomfortable. Some filtered noise patterns judged as uncomfortable are those with a relative decrease in contrast amplitude at high spatial frequencies, compared with the statistics typical of natural images. Decreased amplitude at high spatial frequencies is a characteristic often associated with perceived blur. Additionally, the distribution of contrast across spatial frequencies also provides a cue for the accommodation (focusing) response. The purpose of this study was to investigate the relationship between excess low spatial frequency information, discomfort judgments and perceived blur. Results of these experiments show that a relative reduction in high spatial frequency contrast results in both increased discomfort and perceived blur. This is both in artificial and natural stimuli. A possible explanation for this relationship based on accommodation responses is proposed. © 2013 ARVO

    From cartonera publishing practices to trans-formal methods for qualitative research

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    Interdisciplinarity, multidisciplinarity and counter-disciplinarity are the hallmark of cultural studies and qualitative research, as scholars over the past three decades have discussed through extensive self-reflexive inquiry into their own unstable and ever-shifting methods (Denzin and Lincoln, 2018; Dicks et al., 2006: 78; Grossberg, 2010). Building on the interdisciplinary thought of Jacques Rancière and Caroline Levine on the one hand and traditions of participatory action research and activist anthropology on the other, we bring the methods conversation forward by shifting the focus from disciplines to forms and by making a case for aesthetic practice as qualitative research process. In this paper, the question of methods is approached through the action-based Cartonera Publishing Project with editoriales cartoneras in Latin America – community publishers who make low-cost books out of materials recovered from the street in the attempt to democratise and decolonise literary/artistic production – and specifically through our process-oriented, collaborative work with four cartonera publishers in Brazil and Mexico. Guided by the multiple forms of cartonera knowledge production, which are rooted not in academic research but rather in aesthetic practice and community relations, we offer an innovative ‘trans-formal’ methodological framework, which opens up new pathways for practitioners and researchers to work, think and act across social, cultural and aesthetic forms

    Visual discomfort and depth-of-field

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    Visual discomfort has been reported for certain visual stimuli and under particular viewing conditions, such as stereoscopic viewing. In stereoscopic viewing, visual discomfort can be caused by a conflict between accommodation and convergence cues that may specify different distances in depth. Earlier research has shown that depth-of-field, which is the distance range in depth in the scene that is perceived to be sharp, influences both the perception of egocentric distance to the focal plane, and the distance range in depth between objects in the scene. Because depth-of-field may also be in conflict with convergence and the accommodative state of the eyes, we raised the question of whether depth-of-field affects discomfort when viewing stereoscopic photographs. The first experiment assessed whether discomfort increases when depth-of-field is in conflict with coherent accommodation-convergence cues to distance in depth. The second experiment assessed whether depth-of-field influences discomfort from a pre-existing accommodation-convergence conflict. Results showed no effect of depth-of-field on visual discomfort. These results suggest therefore that depth-of-field can be used as a cue to depth without inducing discomfort in the viewer, even when cue conflicts are large. © 2013 L O'Hare, T Zhang, H T Nefs, P B Hibbard

    Developing a sentinel monitoring network for Scotland's rivers and lochs

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    • The Scottish Environment Protection Agency’s (SEPA) surveillance monitoring networks for rivers and lochs were established over a decade ago to help assess the state of Scotland’s freshwater environment and detect environmental change. This long-term monitoring is integral in formulating evidence-based policy and evaluating whether land and water management aimed at improving environmental quality is effective. • SEPA and Scottish Government have commissioned this review of the surveillance networks to better understand their national representativeness, optimal size and sampling intensities. • The review also considered new and innovative monitoring technologies, and assessed where these may help SEPA to more cost-effectively assess long-term trends in the environment. • The specific aims of this report are: (1) to assess how well the SEPA river surveillance network represents Scotland’s environment; (2) to identify possible changes in the river surveillance network to improve its representativeness; (3) to estimate the ability of the existing river and loch surveillance networks to detect long-term environmental change, and investigate how this might be affected by changes in sampling regimes; (4) to analyse environmental changes detectable since the inception of the surveillance networks; and (5) to analyse the benefits of adopting new sampling methods
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