The recognition of persons is extremely important in considering the safety aspects of residential area lighting. Semi-cylindrical illuminance is the appropriate descriptive parameter, as shown by experiments carried out under real outdoor conditions. The minimum level is used as a basic design criterion. On the other hand, values above 25 lux do not enhance recognition. Other experiments were set up to examine any correlation of modelling effects of the human face with the ratio of vertical to semi-cylindrical illuminance. It is shown that this ratio presents only a geometrical function relative to the object person position. Luminaire concepts are discussed in connection with guidelines for semi-cylindrical illuminance and glare.
On peut conclure que, au cours de la gestation chez la Truie, l'ensemble faeto-placentaire possède les activités enzymatiques nécessaires à la synthèse des oestrogènes.
To obtain realistic results in lighting simulation software, realistic models of light sources are needed. A near-field model of a light source is accurate, and can be obtained by a near-field goniophotometer. This type of goniophotometer is conventionally equipped with a V(λ)-filter. However, the advent of new light sources with spatial- or angular color variations necessitates the inclusion of spectral information about the source. We demonstrate a method to include spectral information of a light source in ray tracing. We measured the relative angular variation of the spectrum of an OLED using a spectroradiometer mounted on a near-field goniophotometer. Principal component analysis (PCA) is exploited to reduce the amount of data that needs to be stored. Also a photometric ray file of the OLED was obtained. To construct a set of monochromatic ray files, the luminous flux in the original ray file is redistributed over a set of wavelengths and stored in separate ray files. The redistribution depends on the angle of emission and the spectral irradiance measured in that direction. These ray files are then inserted in ray tracing software TracePro. Using the OLED as a test source, the absolute spectral irradiance is calculated at an arbitrary position. The result is validated using a spectroradiometer to obtain the absolute spectral irradiance at that particular point. A good agreement between the simulated and measured absolute spectral irradiance is found. Furthermore, a set of tristimulus ray files is constructed and used in ray tracing software to generate a u'v'-color coordinate distribution on a surface. These values are in agreement with the color coordinate distribution found using the spectral ray files. Whenever spectral or color information is desired at a task area, the proposed method allows for a fast and efficient way to improve the accuracy of simulations using ray tracing.
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