BACKGROUND Photoreceptor cells containing melanopsin play a role in the phase-shifting effects of short-wavelength light. In a previous study, we compared the standard light treatment (SLT) of SAD with treatment using short-wavelength blue-enriched white light (BLT). Both treatments used the same illuminance (10,000 lux) and were equally highly effective. It is still possible, however, that nei...

In clinical practice, digital radiographs taken for caries diagnostics are viewed on varying types of displays and usually in relatively high ambient lighting (room illuminance) conditions. Our purpose was to assess the effect of room illuminance and varying display types on caries diagnostic accuracy in digital dental radiographs. Previous studies have shown that the diagnostic accuracy of car...

Illuminance modeling that allows us to mimic or even replicate the dynamics of daylight changes is increasingly becoming a challenge for development more accurate prediction systems natural light availability in building interiors variations insolation at arbitrarily oriented façades. We demonstrate illuminance amplitude due random cloud arrangement can vary over wide range when other atmospher...

We are doing reseaching and development of an intelligent lighting system to provide desired brightness to a desired place. In this study, we consider how to satisfy target illuminance for each worker and minimize power consumption with not only luminous intensity for each light but also the height of luminaire or workers’ seating layout as the design variables. Therefore, highly-accurate targe...

We have measured the illuminance (brightness) of seven neonatal units during both the day and the night. When the units were lit solely by fluorescent tubes the mean illuminance was 348 lux (range 192-690). During the day the mean illuminance was 470 lux (range 236-905). The high dependency regions in four of the seven units were significantly brighter than the corresponding low dependency nurs...

This study aims to analyze the quality of lightings in the indoor badminton courts in Taichung, Taiwan. The study was conducted on-site and illuminance values were analyzed. A digital illuminance meter and handheld distance meter were used as the main measuring tools. Data was collected and analyzed by SPSS for 11.0. The results show that Guoguang Badminton Court has reached the “leisure” grade...

Rovamo et al. [Vision Research (1995), 35, 767-774] measured contrast sensitivity at several frequencies in the fovea and periphery as a function of retinal illuminance, concluding that the critical illuminance for the transition from DeVries-Rose to Weber's laws is proportional to squared frequency at all retinal locations. Yet, inspection of their data clearly reveals that the DeVries-Rose ra...

Autodesk Ecotect TM is an environmental analysis software which according to the U.S. Department of Energy, has not been validated yet. Therefore, the objectives of this research were to validate accuracy of Ecotect TM for thermal and daylighting simulations of buildings and provide recommendations to the Architecture, Engineering and Construction community on application of Ecotect TM . Analys...

An international comparison has been conducted to compare the illuminance responsivity scales (A/lx) and the units of luminous  ux (lm) maintained at the National Institute of Standards and Technology (NIST, USA) and the Helsinki University of Technology (HUT, Finland). Both laboratories realize the illuminance unit by absolutely calibrated photometers and the luminous  ux unit by the absolut...

We evaluated whether a self-screening hypothesis can account for changes in red-green color matches with changes in retinal illuminance and changes in the size of the matching field. The dependence of the color match on field size measured at moderate illuminances was not present at high illuminances. For color matches made with normal pupil entry, there was no need to postulate any factors oth...