Samuel Carré

This paper describes a new optical spectroscopy instrument achieving lock-in detection in all its spectral output channels in a parallel and simultaneous fashion. It is based on two identical compact array spectrometers working in phase quadrature thanks to optical modulators synchronized with an external reference signal. In the application exampl...

This paper presents a study of the spectral characteristics of temporal light modulation in several technologies of lighting products. An optical lock-in spectrometer was designed for this purpose and integrated in a spectral radiant flux measurement facility. It was applied to incandescent and fluorescent lamps, as well as lamps based on white pho...

The recently developed TAIL rating scheme enables assessment of the changes in the indoor environmental quality (IEQ) associated with a building’s deep energy renovation (DER) and classification of the resulting quality levels of the thermal (T), acoustic (A), and luminous (visual) (L) environments and indoor air quality (I). Since the TAIL rating...

In lighting simulations, a luminaire is usually modeled using a luminous intensity distribution emitted by a single-point source. This so-called far-field approach is valid as long as the dimensions of the luminaire are much smaller than the distance to the calculation surface. This assumption is generally not met in standard indoor lighting and ma...

Our approach applied BIM to the urban scale to feed multiscale simulations with input data and to collect results which can be used to create global indicators to evaluate current urban projects, in any field of interest. In our case the whole available data of the territory - including new and existing buildings and infrastructure - of the Nationa...

Correlations between attention, concentration, and physiological reactions during cognitive tasks have been widely studied in different fields and sometimes in interaction with other senses. Several lighting characteristics such as illuminance level and uniformity, color temperature and color rendering indices are known to influence reading perform...

In order to better understand the purpose of parietal art for Palaeolithic groups, its role in society and the different uses it could have, we need to understand which factors impacted the construction of the parietal arrangement, the choice of decorated surfaces and their layout. The first part of this study investigates the nature of the rock su...

Le territoire du Grand Genève connaît l’un des plus forts taux de croissance urbaine d’Europe. Son patrimoine naturel et culturel, sa qualité urbaine et sa qualité de vie sont mis sous tension, en particulier au niveau des lisières urbaines (LU). Interrogeant le rapport entre la ville et la nature, notre hypothèse est que les LU présentent une oppo...

Exposure Limit Values (ELV) for artificial lighting were defined in order to prevent light-induced damage to the retina. The evaluation of the lighting devices include the correction of their spectra by the B(λ) function or blue light hazard function, representing the relative spectral sensitivity of the human eye to the blue light. This weighting...

An appraisal of the effects on human health and the environment of LEDs by the authors of the report of the French health agency ANSES published in 2019.

Recherche et analyse bibliographique, Évaluation du niveau de preuve des effets sanitaires, Caractérisation de l’exposition, Évaluation des risques pour la santé humaine

Ce chapitre constitue une introduction didactique à la physique de l'apparence visuelle. L'aspect mat, les reflets sur des surfaces polies, la brillance, la rétroréflexion, l'anisotropie, les réflexions en couches minces, l'iridescence, la fluorescence et la phosphorescence sont d'abord présentés de manière visuelle. Dans un second temps, plus théo...

Figure S1 Light exposure device.

Figure S2 TUNEL labelling showed no apoptosis in RPE cells.

Figure S3 RPE from rats exposed to 4.14 J/cm2 of fluorescent tubes.

Les résultats présentés dans ce document concernent les terrains sur lesquels le projet Smart Electric Lyon s’est déployé, à savoir, des bâtiments existants. Ces bâtiments appartiennent au secteur Résidentiel et à celui du Tertiaire et des Collectivités locales. Les participants à l’expérimentation (les clients) sont dans une démarche d’amélioratio...

Ageing and alteration of the functions of the retinal pigment epithelium (RPE) are at the origin of lost of vision seen in age-related macular degeneration (AMD). The RPE is known to be vulnerable to high-energy blue light. The white light-emitting diodes (LED) commercially available have relatively high content of blue light, a feature that sugges...

Radiance caching methods have proven to be efficient for global illumination. Their goal is to compute precisely illumination values (incident radiance or irradiance) at a reasonable number of points lying on the scene surfaces. These points, called records, are stored in a cache used for estimating illumination at other points in the scene. Unfort...

Le projet ANR COSIMPHI (CO-Simulation Multi-Physique Interactive - ANR-13-VBDU-0002) s’intéresse à la question de la modélisation multi-physique par la co-simulation pour concevoir des bâtiments en traitant simultanément les ambiances acoustique, visuelle et thermique ainsi que l’efficacité énergétique, environnementale et économique. Cette approch...

Specific objective of the study Imaging detectors are ubiquitous in radiometry and more recently, also gained traction in photometry. The initial challenge was to conciliate the quantum efficiency of silicon-based array sensors with the perceptual photopic sensitivity. Some imaging luminance meter devices (ILMDs) are now able to achieve f1' mismatc...

The retina, the neurosensitive tissue of the eye, is subject to various stresses and environmental factors that can lead to blindness. Several studies have demonstrated that light is potentially harmful to the retina. Recently, the emergence of LED lighting (light emitting diode) updates the problem of retinal toxicity induced by light. These devic...

Spectra of "white LED" are characterized by an intense emission in the blue region of the visible spectrum, absent in day light spectra. This blue component and the high intensity of emission are the main sources of concern about the health risks of LEDs with respect to their toxicity to the eye and the retina. The aim of our study was to elucidate...

An animal experiment was conducted aiming at a better understanding of blue-light retinal toxicity. Freely moving Wistar rats were exposed to intense, blue-rich light for up to eighteen hours. Their retinas were analysed using transmission electron microscopy, Western Blot, immunofluorescence, and Terminal transferase dUTP nick end labelling. This...

Le risque dû à la lumière bleu désigne un phénomène photobiologique par lequel des rayonnements dans un intervalle de longueurs d'onde de +/-100 nanomètres autour de 440 nanomètres induisent des lésions photochimiques au sein de l'épithélium pigmentaire rétinien. Le phénomène a été démontré pour des lésions d'apparition rapide (de quelques heures à...

Radiance caching methods have proven efficient for global illumination. Their goal is to compute precisely illumination values (incident radiance or irradiance) at a reasonable number of points lying on the scene surfaces. These points, called records, are stored in a cache used for estimating illumination of other points in the scene. Unfortunatel...

Le développement d'outils numériques, indispensables pour gérer la complexité grandissante des modes constructifs, nécessite de pouvoir quantifier la précision des résultats obtenus par une approche purement numérique ou combinant essais et calculs. Dans ce contexte, la confiance en la modélisation des phénomènes est un point important, mais il n'e...

Cette présentation illustre l'intérêt des méthodes d'imagerie hyperspectrale pour étudier le risque photobiologique de la lumière bleue émise par des lampes LED et les lampes fluocompactes. L'imagerie hyperspectrale permet de visualiser les zones des lampes qui émettent le plus de lumière bleue phototoxique. Un banc expérimental d'imagerie hyperspe...

We compare two methods for the assessment of the blue light hazard (BLH) of lamps and lamp systems. The first method uses an imaging luminancemeter and a spectrophotometer and relies on the assumption that the spectrum of the source does not vary with the position on its surface and the direction of emission. The second method was devised to allevi...

Irradiance Caching is one of the most widely used algorithms to speed up global illumination. In this paper, we propose an algorithm based on the Irradiance Caching scheme that allows us (1) to adjust the density of cached records according to illumination changes and (2) to efficiently render the high‐frequency illumination changes. To achieve thi...

In this paper, we present a new irradiance caching scheme using Monte Carlo ray tracing for efficiently rendering participating media. The irradiance cache algorithm is extended to participating media. Our method allows to adjust the density of cached records depending on illumination changes. Direct and indirect contributions can be stored in the...

The present study addresses thermal comfort assessment of outdoor and semi-outdoor environments. Two stadium case studies are used to demonstrate the potentiality of the approach that combines wind tunnel data and the calculation of human heat balance due to particular climatic environments. The thermal index PET (physiological equivalent temperatu...

This article presents the luminaire’s near field photometry device developed at CSTB Labs. It is based on the acquisition of pairs (image, illuminance) on a hemisphere surrounding the luminaire. The sensor’s response is calibrated in the photometric space and the luminance samples are aggregated on an enclosing surface representing the luminaire.

This paper presents a new assessment method of the luminous light field around a luminaire. It is based on the acquisition of pairs (image, illuminance) from viewpoints on a hemispheric trajectory around the source. The data provide a dense sampling of the photometric field, smoothly interpolated by merging partial interpolants in the spatial and d...

The paper describes a radiosity method well suited to dynamic changes while requiring less memory compared to classical hierarchical radiosity. Our method relies on the concept of interaction meshes and does not need any computation of links between patches. The light originating at emitters and arriving at a receiving input surface is stored on se...

This paper proposes two methods for selecting the most significant wavelengths in case of spectral rendering. The first, or static method (which can be seen as preprocessing), processes in turn the spectral power distributions (SPDs) of all the light sources to determine those wavelengths for which the SPDs are approximated with an error limit fixe...