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Contrast sensitivity has been measured as a function of the eccentricity along several meridians. The measurements were carried out with a two-dimensional sinusoidal grating (cross grating) presented in a surround with a luminance equal to the average stimulus luminance. The advantage of this stimulus over a one-dimensional grating is that it permits(More)
The contrast sensitivity of the human eye has been measured as a function of eccentricity. The stimulus used was a sine-wave grating with a fixed height of 5’. in a surround of luminance that equals the average stimulus luminance. The measurements were carried out with stimulus width as the independent variable. The “local’. sensitivity for gratings was(More)
The threshold gradient for perception of a linear change in luminance with time has been measured as a function of the stimulus duration. These data are compared with the "De Lange" curves representing the flicker sensitivity measured with intermittent presentation of the stimulus as a function of the stimulus duration. For this purpose it is necessary to(More)
Flicker tresholds have been measured with intermittent stimuli as a function of the presentation time of the stimulus. The periods of flickering light were separated by 1-s dark intervals. Under these conditions the flicker threshold depends on the stimulus duration and on the number of cycles in the stimulus. The "De Lange" curves measured in this way can(More)
Mobile phone data are a new, unprecedented rich source to infer all kinds of mobility related information. The possibilities of mobile data are tremendous, i.e.: crowd images, frequencies of visits, foreign visitors, origin maps, traffic flows and OD-matrices can be generated locally, regionally and nationally and 24/7. The application fields are much(More)
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