Zenith skylight is often distinctly blue during clear civil twilights, and much of this color is due to preferential absorption at longer wavelengths by ozone's Chappuis bands. Because stratospheric ozone is greatly depleted in the austral spring, such decreases could plausibly make Antarctic twilight colors less blue then, including at the zenith. So for several months in 2005, we took digital...

Satellite remotely sensed images with a resolution of 1 m are expected to be available in the near future. These images are well suited for the study of inhomogenous areas like cities. This paper presents research projects of our group concerning the bidirectional reeectance properties of man-made surfaces, such as roofs, streets, etc. The BRDF eeects (like e.g. specular reeection for forward s...

A major interior landscaping project is a central component of a proposed corporate headquarters. While interior landscaping is a significant part of many such projects, typical plant losses of 20-40 percent each year are not acceptable for this installation. The client is confident of their ability to control important factors to sustain plant growth such as soil, irrigation, and plant compati...

Auckland has a temperate climate with comfortable warm, dry summers and mild, wet winters. Auckland house design not only focus on winter thermal performance and indoor thermal condition, but also indoor moisture control, which is closely related to indirect health effects such as dust mites, fungi, etc. Most Auckland houses are designed to use temporary heating for winter indoor thermal comfor...

BACKGROUND This report is about unusual multiple upper extremity concomitant injuries in an adult after a fall from a height. To the best of our knowledge this is the first reported case of concomitant ipsilateral occurrence of multiple common injuries, uncommonly occurring together in a single traumatic episode. CASE REPORT A 36-year-old right-handed man fell through a skylight to the floor ...

The usual answer to the question ‘‘Why is the sky blue?’’ is based only on Rayleigh scattering from the molecules in the atmosphere and makes little mention of the contribution of color vision. We supplement this answer with a quantitative discussion of the role color vision plays in determining the appearance of the daytime sky. The anatomy of the human eye is reviewed, and its response as a f...

Many animals can use the polarization of light in various behavioural contexts. Birds are well known to use information from the skylight polarization pattern for orientation and compass calibration. However, there are few controlled studies of polarization vision in birds, and the majority of them have not been successful in convincingly demonstrating polarization vision. We used a two-alterna...

Recovering shadows is an important step for many vision algorithms. Current approaches that work with time-lapse sequences are limited to simple thresholding heuristics. We show these approaches only work with very careful tuning of parameters, and do not work well for long-term timelapse sequences taken over the span of many months. We introduce a parameter-free expectation maximization approa...

Recent studies of the iconic fall migration of monarch butterflies have illuminated the mechanisms behind their southward navigation while using a time-compensated sun compass. Skylight cues, such as the sun itself and polarized light, are processed through both eyes and are probably integrated in the brain's central complex, the presumed site of the sun compass. Time compensation is provided b...

We present a method for the efficient re-rendering of a scene under a directional illuminant at an arbitrary orientation. We take advantage of the linearity of the rendering operator with respect to illumination for a fixed scene and camera geometry. Re-rendering is accomplished via linear combination of a set of prerendered "basis" images. The theory of steerable functions provides the machine...