Catálogo de publicaciones - revistas

<jats:p> Correlated color temperature (CCT) is a one-dimensional metric that aims to quantify the perceived visual quality of nominal white light sources. It is often used as a proxy for the color quality of light sources due to its ease of use. However, CCT lacks the accuracy in communicating color information for research purposes. Two light sources with identical CCTs can appear perceptually different, and these differences are not estimated by CCT due to the loss of information caused by reducing spectral power distribution of light sources into a one-dimensional metric. Using supplemental metrics in addition to CCT, providing the absolute spectral power distribution of light sources in graphical and tabular form, and documenting and accounting for potential confounding factors, such as chromatic adaptation, can increase the validity of research results, improve the repeatability of studies, and help address replication concerns. </jats:p>

<jats:p> Visual comfort plays a central role in building occupants’ comfort, well-being and productivity. It is therefore fundamental to meet the occupants’ visual and lighting needs, carefully accounting for the room layout, usage and activities. In this framework, physiotherapy centres constitute a peculiar case since they are occupied by therapists and patients from different age groups, engaged in various activities performed in different positions in the rooms, and affected by different health issues. Lighting quality and satisfaction were monitored in four physiotherapy centres in Northern Italy and Denmark. Subjective assessments were compared with objective illuminance measurements at the task areas, and the sites were also analysed in terms of window and architectural features. Moreover, the interaction between visual and other environmental perceptions was studied. The results revealed: (1) positive influence of daylight access on the satisfaction of occupants; (2) occupants’ complaints about low lighting levels associated with artificial lighting being unable to provide 300 lx and natural light not balancing this lack of illumination; and (3) lower satisfaction among therapists, who also showed the tendency to assess their environmental perception more globally, since correlations between light and daylight satisfaction and other stimuli were observed when comfort issues were present. </jats:p>

<jats:p> Previous studies have suggested mixed results about the effect of road lighting on crime. One potential explanation is that the effect of lighting, if any, varies with the type of crime. This was tested through analysis of the effect of change in ambient light level on crimes recorded in 11 cities in the USA for the 10-year period 2010–2019. The results suggest that ambient light level had a consistent effect on robbery, with darkness leading to an increase in robbery, but did not suggest a significant effect for other types of crime. </jats:p>

<jats:p> Modern high-resolution headlamp systems are capable of adjusting to different driving situations. However, the existing road lighting is not yet taken into account when setting the headlamp’s light distribution. This article investigates the influence of the automotive headlamp systems on the visibility of targets in different road lighting conditions and proposes a new lighting strategy based on these results. The luminances of square targets of different surface reflectances and at different distances ahead of the vehicle were measured in road lighting designed to meet classes varying from M3 to M6. For each combination the visibility level (VL) of the targets was determined, with road lighting alone and also when additionally illuminating the scene with the car headlamps. The influence of the headlamps on target visibility was found to depend on the road lighting class, the target distance and its reflectance. In some situations, additional light from the headlamp decreased the target VL and therefore the probability that a driver would detect it. Different ranges of headlamp light distribution were proposed for different road lighting classes to bring light only where it is needed. </jats:p>

<jats:p> Photoluminescent paints for road marking application have been evaluated through laboratory measurements and visibility computations. The luminance decay in the dark was measured after constant excitation during at least 6 hours. To study the effect of night-time lighting conditions, luminance was measured under a constant low illumination (simulating moon and light pollution), and a periodic lighting, simulating automotive traffic. Measurements were also carried out on luminescent road marking applied on real pavement in a full-scale mock-up. Then, possible uses and limits of photoluminescent road markings were investigated through visibility computations based on the COST 331 model. Findings suggest luminescent road markings could strengthen the visual guidance of drivers on the road with traffic by increasing the visibility distance beyond the headlamp beams during the first few hours of the night, and in unlit areas such as bicycle paths, but the performance depends on the night-time illumination level. </jats:p>

<jats:p> The reflection properties of pavement have an impact on the lit environment and thus upon drivers’ vision and comfort and the energy consumption of the lighting installation. The reflection properties combine diffuse and specular components. The specular reflection component changes with different materials: it also changes when the surface is wet, although this is sometimes ignored in lighting design. This study used simulation (DIALux 4.13) to investigate the effect on lighting parameters (luminance, overall uniformity, longitudinal uniformity and threshold increment (TI)) of changes in pavement reflection properties using different pavement materials and under dry and wet conditions. Furthermore, comparison of lighting parameters was made with different road lighting arrangements. The results show that an increase in the specular reflection component leads to an increase in luminance and a decrease in uniformity. Of the surfaces investigated, the porous pavement had the lower luminance but better uniformity. Arranging the lighting installation based on the extreme wettest condition could make luminance and uniformity rise but with an increase of 2–2.5 kWh/m<jats:sup>2</jats:sup> annual energy consumption. When trying to control glare problems during design process, it is suggested that uniformity cannot be neglected except the TI. </jats:p>

<jats:p> In this study, the photometry of a wide range of conventional and innovative pavements used in urban and interurban areas was characterised with a laboratory gonioreflectometer, both in new condition and after 30 months of natural ageing. An extreme diversity of behaviour with respect to light reflection has been demonstrated, both over time and between pavements. Various lighting studies have been carried out for cases of renewal of lighting installation with the installation of LED luminaires on poles in place. The calculations have shown that the use of typical CIE r-tables almost systematically leads to non-compliance with the EN 13201 standard, particularly in terms of uniformity. On the other hand, taking into account in the calculations, the photometry of the pavement in its stabilised state makes it possible both to respect the challenges of lighting safety and to achieve significant energy savings. As measurements of pavement photometry are rarely carried out, an alternative is to set up a database of urban pavements, which is one of the achievements of this research. </jats:p>