Congress and the war. A radio discussion.

Round Table, nr. 237.OPLADEN-RUG0

Range image statistics can explain the anomalous perception of length

A long-standing puzzle in visual perception is that the apparent extent of a spatial interval (e.g., the distance between two points or the length of a line) does not simply accord with the length of the stimulus but varies as a function of orientation in the retinal image. Here, we show that this anomaly can be explained by the statistical relationship between the length of retinal projections and the length of their real-world sources. Using a laser range scanner, we acquired a database of natural images that included the three-dimensional location of every point in the scenes. An analysis of these range images showed that the average length of a physical interval in three-dimensional space changes systematically as a function of the orientation of the corresponding interval in the projected image, the variation being in good agreement with perceived length. This evidence implies that the perception of visual space is determined by the probability distribution of the possible real-world sources of retinal images

Wildlife in Airport Environments: Appendix, Index and Back Cover

In 1990, the 190 member nations of the International Civil Aviation Organization (ICAO) adopted, in Annex 14 to the Convention on Civil International Aviation, three recommended management practices regarding bird hazards to aviation. The recommended practices required that aviation authorities within each nation (1) assess the extent of the hazard posed by birds at and in the vicinity of airports certificated for passenger traffic, (2) take necessary action to decrease the number of birds, and (3) eliminate or prevent the establishment of any site in the vicinity of the airport that could attract birds and thereby present a danger to aviation. Because of the increasing threat posed by birds to aviation worldwide, member states voted to make these recommendations mandatory ICAO standards, effective November 2003. In 2009, ICAO expanded these standards to include terrestrial wildlife such as large mammals and reptiles that pose a risk at airports (ICAO 2009)