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International audience; The goal of Mixed Reality (MR) is to achieve a seamless and realistic blending between real and virtual worlds. This requires the estimation of reflectance properties and lighting characteristics of the real scene. One of the main challenges within this task consists in recovering such properties using a single RGB-D camera. In this paper, we introduce a novel framework to recover both the position and color of multiple light sources as well as the specular reflectance of real scene surfaces. This is achieved by detecting and incorporating information from both specular reflections and cast shadows. Our approach is capable of handling any textured surface and considers both static and dynamic light sources. Its effectiveness is demonstrated through a range of applications including visually-consistent mixed reality scenarios (e.g. correct real specularity removal, coherent shadows in terms of shape and intensity) and retexturing where the texture of the scene is altered whereas the incident lighting is preserved.

Maurice de Guérin a trouvé en Charles Du Bos de fraternels prolongements posthumes : même intérêt pour le spirituel, l’imaginaire, l’écriture, l’introspection ; mêmes questions obsédantes quant à l’unité, la dispersion du moi ; même manière d’échapper à l’œuvre cathédrale à travers des petits blocs de prose ou des fragments. Cette relation parallèle permet de suivre les variations interprétatives de Guérin en Du Bos et inversement. C’est ce fonctionnement spéculaire et exégétique que nous abordons ici., Maurice de Guérin found in Charles Du Bos fraternal posthumous influences: the same interest in the spiritual, the imaginary, writing, introspection; the same obsessive questions about the unity, the dispersion of the self; the same way of escaping the cathedral work through small blocks of prose or fragments. This parallel relationship allows us to follow the interpretative variations of Guérin in Du Bos and vice versa. Here we address this specular and exegetical function.

International audience; Specular and mirror-like surfaces are difficult to reconstruct by the fact that light of the surrounding environment is reflected off the surface. Nowadays, it is still a challenge in many application fields to get a fast and accurate reconstruction of specular objects. 3D acquisition by deflectometry involves estimating the 3D profile of a specular surface by analyzing the image of a light source or a pattern captured by a camera after reflection on the surface. These techniques require the knowledge of the location and the orientation of the camera and the orientation of the light source. If camera calibration is a process widely known and controlled and guaranteeing good accuracy, estimating the orientation of the light source is still an issue. We propose to overcome it by using a light source whose the color changes according to the orientation. Indeed, we implement a vision system of light source's position recognition by the color in simulation with the 3D computer graphics software Blender, we define a calibration technique and we suggest some possible light sources to export our simulated vision system to reality. Plus, we explore the potential benefit of light field in order to model such a system.

Understanding and management of light is of great importance for nanoscale devices. This report demonstrates enhanced absorption, photoluminescence and scattering in InP nanowires when coated with dielectric polymer shell. The shells increase absorption and emission by a factor of ~2 and photoluminescence by a factor of ~4. A thorough optical characterization is provided, including reflectance, transmission, luminescence and scattering to incident and transmitted directions. From this characterization, we derive the distribution of absorbed light within the structure (InP nanowires, Au seed particles and the substrate). Additionally, reflectance, transmission and emission are shown to become increasingly diffuse with the dielectric shells. The results are thought to provide better understanding in light-matter interaction in nanostructures, as well as to provide valuable tools for light and scattering management in nanoscale optoelectronics.

Highlights • Designing homogeneous lighting system for a photobioreactor in undergone. • Bright and dull side reflectivities of household aluminum foil are measured. • They have dramatically different diffuse and specular components. • Total reflectivity is the same over the spectrum for both sides. • These measurement are applied to achieve uniform intensity lighting., This work reports the design of a light concentrator intended to be used to cast uniform lighting over a photobioreactor. Household aluminum foils was chosen as reflective material to build the concentrator. This choice raised the question of which side to use. Thus measurements of household aluminum foil reflectivity spectra on both bright and matte sides were undergone. These measurements were done using an integrating sphere, over a 250–2500 nm range. Diffuse and total reflectivities were acquired, for two samples each time. The obtained results are very repeatable and in good agreement with literature on rolled aluminum sheets, for the bright side at least, as matte side data were not found. Specular reflectivity is higher for the bright side while diffuse reflectivity is higher for the matte one. Furthermore, both sides of the foil have the same total reflectivity, around 86 % in the visible range of the spectrum, 97% in the near infrared. Our measurements are readability usable and available as supplementary materials. Finally, we applied these findings to the in silico design of lab scale light concentrator illuminating a new photobioreactor. A modified version of the raytracing software Soltrace was used to determine which of the two sides of our household aluminum foil was be best suited for our application.

Dans Thérèse mon amour, Julia Kristeva nous propose une configuration énonciative et narrative qui interpelle notre réflexe habitué à la distinction nette des strates de l’énonciation. L’on découvre un jeu spéculaire, un jeu de miroirs qui souvent confond les voix, et de cette configuration apparait toute une galerie de portraits : on y aperçoit le portrait du personnage principal, Thérèse d’Avila, la mystique carmélite de l’Espagne du seizième siècle. Il y a également la voix – portrait de la narratrice, Sylvia Leclercq, qui raconte et se raconte. Derrière le portrait de la narratrice nous entrevoyons les traces de l’auteur, de son ethos assez révélateur d’un portrait qui, au fil du récit, se construit à petites touches. Les trois instances ont ceci de commun qu’elles s’expriment au féminin, un féminin que l’on décrit et qui se décrit, pour dire, par-delà les siècles, le même souci, la même quête, celle du sens., En Thérèse mon amour, Julia Kristeva propone una configuración enunciativa y narrativa que desafía nuestro reflejo habitual a la clara distinción de los estratos de enunciación. Descubrimos un juego especular, un juego de espejos que a menudo confunde las voces, y de esta configuración aparece una galería completa de retratos : vemos el retrato del personaje principal, Teresa de Ávila, la mística carmelita de la España del siglo XVI. También está la voz - retrato de la narradora, Sylvia Leclercq, quien cuenta y cuenta historias. Detrás del retrato del narrador vislumbramos las huellas del autor, su ethos revela un retrato que, a medida que se desarrolla la historia, tiene pequeños toques. Los tres casos tienen algo en común : se expresan en lo femenino, un femenino que se describe y describe, por decirlo así, más allá de los siglos, con la misma preocupación, la misma búsqueda, la del significado., Em Thérèse mon amour, Julia Kristeva propõe uma configuração enunciativa e narrativa que desafia nosso reflexo habitual à clara distinção dos estratos da enunciação. Descobrimos um jogo especular, um jogo de espelhos que muitas vezes confunde as vozes, e dessa configuração aparece toda uma galeria de retratos : vemos o retrato da personagem principal, Teresa de Ávila, a mística carmelita de Espanha do século XVI. Há também a voz - retrato da narradora, Sylvia Leclercq, que conta e conta histórias. Por trás do retrato do narrador, vislumbramos os traços do autor, seu ethos bastante revelador de um retrato que, à medida que a história se desenrola, é construído com pequenos toques. As três instâncias têm em comum o fato de se expressarem no feminino, um feminino descrito e descrito, para dizer, além dos séculos, a mesma preocupação, a mesma busca, a de significado., In Thérèse mon amour, Julia Kristeva proposes an enunciative and narrative configuration that challenges our habitual reflex to the clear distinction of the strata of enunciation. We discover a specular game, a game of mirrors that often confuses the voices, and from this configuration appears a whole gallery of portraits : we can see the portrait of the main character, Thérèse d’Avila, the Carmelite mystic of Spain of the sixteenth century. There is also the voice - portrait of the narrator, Sylvia Leclercq, who tells and tells stories about herself. Behind the portrait of the narrator we glimpse the traces of the author, his ethos quite revealing a portrait that, over the story, is built small strokes. The three instances have the same things in common : they express themselves in the feminine, a feminine that is described, a feminine who describe, to say, beyond centuries, the same concern, the same quest, the meaning., Trayectorias Humanas Trascontinentales, N° 6 | 2019

We present a novel approach to real-time dense visual simultaneous localisation and mapping. Our system is capable of capturing comprehensive dense globally consistent surfel-based maps of room scale environments and beyond explored using an RGB-D camera in an incremental online fashion, without pose graph optimization or any post-processing steps. This is accomplished by using dense frame-to-model camera tracking and windowed surfel-based fusion coupled with frequent model refinement through non-rigid surface deformations. Our approach applies local model-to-model surface loop closure optimizations as often as possible to stay close to the mode of the map distribution, while utilizing global loop closure to recover from arbitrary drift and maintain global consistency. In the spirit of improving map quality as well as tracking accuracy and robustness, we furthermore explore a novel approach to real-time discrete light source detection. This technique is capable of detecting numerous light sources in indoor environments in real-time as a user handheld camera explores the scene. Absolutely no prior information about the scene or number of light sources is required. By making a small set of simple assumptions about the appearance properties of the scene our method can incrementally estimate both the quantity and location of multiple light sources in the environment in an online fashion. Our results demonstrate that our technique functions well in many different environments and lighting configurations. We show that this enables (a) more realistic augmented reality rendering; (b) a richer understanding of the scene beyond pure geometry and; (c) more accurate and robust photometric tracking.

The overarching goal of Mixed Reality (MR) is to provide the users with the illusion that virtual and real objects coexist indistinguishably in the same space. An effective illusion requires an accurate registration between both worlds. This registration must be geometrically and photometrically coherent. In this thesis, we propose novel photometric registration methods to estimate the illumination and reflectance of real scenes. Specifically, we propose new approaches which address three main challenges: (1) use of a single RGB-D camera. (2) estimation of both diffuse and specular reflectance properties. (3) estimation of the 3D position and color of multiple dynamic light sources. Within our first contribution, we consider indoor real scenes where both geometry and illumination are static. As the sensor browses the scene, specular reflections can be observed throughout a sequence of RGB-D images. These visual cues are very informative about the illumination and reflectance of scene surfaces. Hence, we model these cues to recover both diffuse and specular reflectance properties as well as the 3D position of multiple light sources. Our algorithm allows convincing MR results such as realistic virtual shadows and correct real specularity removal. Shadows are omnipresent and result from the occlusion of light by existing geometry. They therefore represent interesting cues to reconstruct the photometric properties of the scene. Presence of texture in this context is a critical scenario. In fact, separating texture from illumination effects is often handled via approaches which require user interaction or do not satisfy mixed reality processing time requirements. We address these limitations and propose a method which estimates the 3D position and intensity of light sources. The proposed approach handles dynamic light sources and runs at an interactive frame rate. The existence of a light source is more likely if it is supported by more than one cue. We therefore address the problem of estimating illumination and reflectance properties by jointly analysing specular reflections and cast shadows. The proposed approach takes advantage of information brought by both cues to handle a large variety of scenes. Our approach is capable of handling any textured surface and considers both static and dynamic light sources. Its effectiveness is demonstrated through a range of applications including real-time mixed reality and retexturing. Since the detection of cast shadows and specular reflections are at the heart of this thesis, we further propose a deep-learning framework to jointly detect both cues in indoor real scenes.; L'objectif principale de la Réalité Mixte (RM) est de donner aux utilisateurs l'illusion que les objets virtuels et réels coexistent indistinctement dans le même espace. Une illusion efficace nécessite un recalage précis entre les deux mondes. Ce recalage doit être cohérent du point de vue géométrique et photométrique. Dans cette thèse, nous proposons de nouvelles méthodes de recalage photométrique pour estimer l'illumination et la réflectance de scènes réelles. Plus précisément, nous proposons des approches en nous attaquant à trois grands défis : (1) utilisation d'une seule caméra RGB-D. (2) estimation des propriétés de réflectance diffuse et spéculaire. (3) estimation de la position 3D et de la couleur de sources lumineuses dynamiques multiples. Dans notre première contribution, nous considérons des scènes réelles d’intérieurs où la géométrie et l'éclairage sont statiques. En observant la scène à partir d’une caméra mobile, des réflexions spéculaires peuvent être détectées tout au long de la séquence d'images RGB-D. Ces indices visuels sont très instructifs sur l'éclairage et la réflectance des surfaces des scènes. Par conséquent, nous les modélisons pour estimer à la fois les propriétés de réflectance diffuse et spéculaire ainsi que la position 3D de sources lumineuses multiples. Notre algorithme permet d'obtenir des résultats de RM convaincants tels que des ombres virtuelles réalistes ainsi qu'une suppression correcte de la spécularité réelle. Les ombres sont omniprésentes et représentent l’occultation de la lumière par la géométrie existante. Elles représentent donc des indices intéressants pour reconstituer les propriétés photométriques de la scène. La présence de texture dans ce contexte est un scénario critique. En effet, la séparation de la texture et des effets d'éclairage est souvent gérée par des approches qui nécessitent l’intervention de l'utilisateur ou qui ne répondent pas aux exigences du temps de traitement de la réalité mixte. Nous abordons ces limitations et proposons une méthode d'estimation de la position et de l'intensité des sources lumineuses. L'approche proposée gère les lumières dynamiques et fonctionne en temps quasi-réel. L'existence d'une source lumineuse est plus probable si elle est soutenue par plus d'un indice visuel. Nous abordons donc le problème de l'estimation des propriétés d’éclairage et de réflectance en analysant conjointement les réflexions spéculaires et les ombres projetées. L'approche proposée tire parti de l'information apportée par les deux indices pour traiter une grande variété de scènes. Notre approche est capable de traiter n'importe quelle surface texturée et tient compte à la fois des sources lumineuses statiques et dynamiques. Son efficacité est démontrée par une gamme d'applications, incluant la réalité mixte et la re-texturation. La détection des ombres projetées et des réflexions spéculaires étant au cœur de cette thèse, nous proposons finalement une méthode d'apprentissage approfondi pour détecter conjointement les deux indices visuels dans des scènes réelles d’intérieurs.

With the recent increase in numbers of small and versatile low-power meteor radars, the opportunity exists to benefit from simultaneous application of multiple systems spaced by only a few hundred km and less. Transmissions from one site can be recorded at adjacent receiving sites using various degrees of forward scatter, potentially allowing atmospheric conditions in the mesopause regions between stations to be diagnosed. This can allow a better spatial overview of the atmospheric conditions at any time. Such studies have been carried out using a small version of such so-called multistatic meteor radars, e.g. Chau et al. (Radio Sci 52:811–828, 2017, https://doi.org/10.1002/2016rs006225 ). These authors were able to also make measurements of vorticity and divergence. However, measurement uncertainties arise which need to be considered in any application of such techniques. Some errors are so severe that they prohibit useful application of the technique in certain locations, particularly for zones at the midpoints of the radars sites. In this paper, software is developed to allow these errors to be determined, and examples of typical errors involved are discussed. The software should be of value to others who wish to optimize their own MMR systems.

International audience; Photometric registration consists in blending real and virtual scenes in a visually coherent way. To achieve this goal, both reflectance and illumination properties must be estimated. These estimates are then used, within a rendering pipeline, to virtually simulate the real lighting's interaction with the scene. In this paper, we are interested in indoor scenes where light bounces off of objects with different reflective properties (diffuse and/or specular). In these scenarios, existing solutions often assume distant lighting or limit the analysis to a single specular object. We address scenes with various objects captured by a moving RGB-D camera and estimate the 3D position of light sources. Furthermore, using spatio-temporal data, our algorithm recovers dense diffuse and specular reflectance maps. Finally, using our estimates, we demonstrate photo-realistic augmentations of real scenes (virtual shadows, specular occlusions) as well as virtual spec-ular reflections on real world surfaces.

We report a low-cost optical method with high sensitivity for the quantitative assessment of the gloss of human skin in the low gloss regime relevant for physiological skin gloss conditions. Using Monte Carlo simulations, experiments on gloss calibration standards and in-vivo skin gloss experiments using an optical prototype, we demonstrate the improved sensitivity of the proposed method in the low gloss regime compared to professional industrial and skin gloss measurement devices.

International audience; Dynamic visual information facilitates three-dimensional shape recognition. It is still unclear, however, whether the motion information generated by moving specularities across a surface is congruent to that available from optic flow produced by a matte-textured shape. Whereas the latter is directly linked to the first-order properties of the shape and its motion relative to the observer, the specular flow, the image flow generated by a specular object, is less sensitive to the object's motion and is tightly related to second-order properties of the shape. We therefore hypothesize that the perceived bumpiness (a perceptual attribute related to curvature magnitude) is more stable to changes in the type of motion in specular objects compared with their matte-textured counterparts. Results from two two-interval forced-choice experiments in which observers judged the perceived bumpiness of perturbed spherelike objects support this idea and provide an additional layer of evidence for the capacity of the visual system to exploit image information for shape inference.

International audience; For the first time, a personal exposimeter (PE) for 60 GHz radiation measurements is presented. The PE is designed based on numerical simulations, on-phantom and on-body calibration measurements under specular and diffuse exposure to determine the antenna aperture and measurement uncertainty of the PE. A 95% prediction interval of 6.6 dB is obtained for the PE's response using a combination of three nodes with different polarizations. The response of the PE is in the range of 0.7 to 1.2 for specular and diffuse fields. © 2017 EAI.

We considered whether optic flow generated by 3D relief of a foreground surface might influence visually-mediated self-motion perception (vection). We generated background motion consistent with self-rotation, and a foreground object with bumpy relief was either rotated with the observer (ego-centric) or fixed in world coordinates (world-centric). We found that vection strength ratings were greater in conditions with world-centric retinal motion of the foreground object, despite generating flow that was opposite to background motion. This effect was explained by observer judgments of the axis self-rotation in depth; whereas ego-centric flow generated experiences of more on-axis self-rotation, world-centric flow generated experiences of centrifugal rotation around the foreground object. These data suggest that foreground object motion can increase the perception of self-motion generated by optic flow, even when they reduce net retinal motion coherence and promote conditions for multisensory conflict. This finding supports the view that self-motion perception depends on mid-level representations of whole-scene motion.

The spectral specular reflectance of conventional and novel reflective materials for solar concentrators is measured with an acceptance angle of 17.5 mrad over the wavelength range 300−2500 nm at incidence angles 15–60° using a spectroscopic goniometry system. The same experimental setup is used to determine the spectral narrow-angle transmittance of semi-transparent materials for solar collector covers at incidence angles 0–60°. In addition, the angle-resolved surface scattering of reflective materials is recorded by an area-scan CCD detector over the spectral range 350–1050 nm. A comprehensive summary, discussion, and interpretation of the results are included in the associated research article “Spectral reflectance, transmittance, and angular scattering of materials for solar concentrators” in Solar Energy Materials and Solar Cells., Data in Brief, 6, ISSN:2352-3409

The objective of the work is to model the shape of the sinusoidal shape of regular water waves generated in a laboratory flume. The waves are traveling in time and render a smooth surface, with no white caps or foam. Two methods are proposed, treating the water as a diffuse and specular surface, respectively. In either case, the water is presumed to take the shape of a traveling sine wave, reducing the task of the 3D reconstruction to resolve the wave parameters. The first conceived method performs the modeling part purely in 3D space. Having triangulated the points in a separate phase via bundle adjustment, a sine wave is fitted into the data in a least squares manner. The second method presents a more complete approach for the entire calculation workflow beginning in the image space. The water is perceived as a specular surface, and the traveling specularities are the only observations visible to the cameras, observations that are notably single image. The depth ambiguity is removed given additional constraints encoded within the law of reflection and the modeled parametric surface. The observation and constraint equations compose a single system of equations that is solved with the method of least squares adjustment. The devised approaches are validated against the data coming from a capacitive level sensor and on physical targets floating on the surface. The outcomes agree to a high degree.

In this thesis the work is based around the HELIOS (High Energy Laser Induced Overtone Source) laboratory, a facility at the Division of Molecular and Condensed Matter Physics at the Department of Physics and Astronomy, Uppsala University, Sweden. HELIOS generates XUV (extreme ultraviolet) photon pulses with energies between 15-70 eV and pulse lengths shorter than 50 fs. It is believed that the grating in the monochromator of the lab introduces a chirp, meaning that the different constituent energies of the pulse will be ordered in an non homogeneous way. Since the lab is striving to create as short pulses with as high temporal resolution as possible, learning more about any effects that might change the pulse is of great interest. If the source of the chirp effect is known then possible countermeasures can start being discussed. To investigate the pulse a numerical ray trace is performed for a XUV pulse passing through the monochromator using the BeamFour© software. A pulse consisting of 49500 rays with mean energy 40 eV and FWHM 0.5 eV was traced, but no clear dependence between wavelength and the pulse length could be observed. This seems to indicate that there either is no chirp present in the monochromator or that it is of such a small order that higher certainty (more rays) will be required to observe it. I detta examensarbete baseras arbetet på HELIOS-laboratoriet (High Energy Laser Induced Overtone Source), en anläggning vid avdelningen för molekyl- och kondenserade materiens fysik, institutionen för fysik och astronomi, Uppsala universitet, Sverige. Vid HELIOS genereras XUV (extremt ultravioletta) fotonpulser med energier mellan 15- 70 eV och pulslängder under 50 fs. Vid avdelningen tror man att gittret i laboratoriets monokromator introducerar en så kallad chirp, vilket innebär att de olika energierna som bygger upp pulsen blir uppdelade i en icke homogen ordning. Eftersom labbet strävar efter att skapa så korta oc kompakta pulser som möjligt är det av stort intresse för avdelningen att lära sig mer om effekter som påverkar pulsens form. Om utsträckningen av sådana effekter är välkänd så kan man börja diskutera åtgärder för att motverka dessa, eller åtminstone vara medveten om dem. För att undersöka hur pulsen beter sig så har en numerisk strålspårning utförts för en XUV-puls med hjälp av programvaran BeamFour© . En puls innehållande 49500 strålar med genomsnittlig energi 40 eV och halvvärdesbredd (FWHM) 0.5 eV spårades, men inget tydligt beroende mellan våglängd och pulslängd kunde observeras. Detta tyder på att det antingen inte uppstår någon chirp i monokromatorn, alternativt att den är av sådan liten storlek att högre mätsäkerhet (fler strålar) kommer behövas för att observera den.

Avaliou-se a espessura corneana central de 13 gatos normais com microscópio especular de não-contato Topcon SP-2000P e paquímetro ultra-sônico. Foi observado aumento da espessura corneana mensurada pelo paquímetro ultra-sônico comparado ao microscópio especular.The central corneal thickness of 13 normal cats was evaluated by a Topcon SP-2000P noncontact specular microscope and by an ultrasonic pachymetry was evaluated. An increase on the corneal thickness measured by ultrasonic pachymetry as compared to the specular microscope was observed.

Light interacts with an organism's integument on a variety of spatial scales. For example in an iridescent bird: nano-scale structures produce color; the milli-scale structure of barbs and barbules largely determines the directional pattern of reflected light; and through the macro-scale spatial structure of overlapping, curved feathers, these directional effects create the visual texture. Milli-scale and macro-scale effects determine where on the organism's body, and from what viewpoints and under what illumination, the iridescent colors are seen. Thus, the highly directional flash of brilliant color from the iridescent throat of a hummingbird is inadequately explained by its nano-scale structure alone and questions remain. From a given observation point, which milli-scale elements of the feather are oriented to reflect strongly? Do some species produce broader "windows" for observation of iridescence than others? These and similar questions may be asked about any organisms that have evolved a particular surface appearance for signaling, camouflage, or other reasons. In order to study the directional patterns of light scattering from feathers, and their relationship to the bird's milli-scale morphology, we developed a protocol for measuring light scattered from biological materials using many high-resolution photographs taken with varying illumination and viewing directions. Since we measure scattered light as a function of direction, we can observe the characteristic features in the directional distribution of light scattered from that particular feather, and because barbs and barbules are resolved in our images, we can clearly attribute the directional features to these different milli-scale structures. Keeping the specimen intact preserves the gross-scale scattering behavior seen in nature. The method described here presents a generalized protocol for analyzing spatially- and directionally-varying light scattering from complex biological materials at multiple structural scales.

A new reflectometer-spectrophotometer has been designed and constructed using state-of-the-art technology to enhance optical properties of materials measurements over the ultraviolet, visible, and near-infrared (UV-Vis-NIR) wavelength range (200 nm to 2500 nm ). The instrument, Spectral Tri-function Automated Reference Reflectometer (STARR), is capable of measuring specular and diffuse reflectance, bidirectional reflectance distribution function (BRDF) of diffuse samples, and both diffuse and non-diffuse transmittance. Samples up to 30 cm by 30 cm can be measured. The instrument and its characterization are described.

International audience; This study focuses on the directionality of wheat leaf reflectance as a function of leaf surface characteristics. Wheat leaf BRF measurements were completed under 45° zenith illumination angle in three visible broad spectral bands with a conoscope that provides very high angular resolution data over a large portion of the whole hemisphere, including around the illumination direction. The measurements show a clear anisotropy with a specular lobe in the forward scattering direction and a small but significant hotspot feature in the backward scattering direction. The BRF directional features further depend on the illumination orientation because of the leaf roughness created by longitudinal veins: the specular lobe was more pronounced when the illumination was perpendicular to the veins, while specular reflection was more spread over azimuths for longitudinal illumination. Moreover, a sharp hotspot feature was observed for transversal illumination where the apparent roughness is the largest. The scattering was tentatively decomposed into specular, hotspot and isotropic components. Results showed that the hotspot contribution to the directional hemispherical reflectance factor (DHRF) was marginal conversely to that of the specular component that ranges between 0.036 and 0.050 (absolute DHRF value). The specular component was almost the same in the three visible bands considered. The isotropic component originating from volume scattering was contributing the most to the DHRF and was depending on wavelength, ranging between 0.055 and 0.097 in absolute DHRF value. A simple model was proposed to estimate the volume scattering from the isotropic and the surface components. Consequences of these findings were drawn on the ability to estimate leaf biochemical composition independently from leaf surface scattering, as well as on the interpretation of remote sensing at the canopy level.

Veiling glare is the phenomenon when the dashboard or parts of the dashboard reflects into the windshield and creates veiling images. These images are both disturbing and impair the driver’s vision of the road scene. Cars are today more and more designed to have a "dynamic" expression with further raked windshields and the designers also wants to have the possibility to use lighter colors in the interior. This can lead to unwanted consequences in the form of an increased amount of reflections from the dashboard into the windshield. The goal with this thesis was to describe a measurable requirement that correlates with customer expectations together with different positions and angles of the light source, windshield and dashboard, material attributes of the dashboard and windshield characteristics like anti-reflective coating. The thesis work was carried out at the department of Human Factors Engineering and Ergonomics at Volvo Car Corporation, Gothenburg. There is an existing requirement that restrict the gloss and lightness of the instrument panel top surface. This requirement is valid at the specular sun angle (geometric relationship which creates a direct reflection from the light source into the driver’s eyes), which gives the gloss a much larger effect in the requirement compared to lightness. Volvo Cars has realized through own observations, that instrument top panel lightness plays an important role in the experience of veiling glare, particularly at high sun angles. Therefore Volvo Cars has created a complementing requirement that express a maximum lightness value based on a linear relationship tied to the windscreen angle. The problem is that it doesn't exist any linear relationships when the phenomenon veiling glare is examined further. In a laboratory environment a measuring method was developed to research the affecting factors of veiling glare at high sun angles. This work has been done through the use of several quality tools as Design of Experiment and Binary Logistic Regression. A subjective survey was performed to determine the customer acceptance for veiling glare at for different road scenes. The result from these studies was then combined to express maximum lightness value tied to geometrical properties between the windshield and the dashboard. Validerat; 20101217 (root)

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:56:03Z No. of bitstreams: 1 S0102-09352008000200013.pdf: 136079 bytes, checksum: 2b521c39e7e5a88a9047496f4f8dbb79 (MD5) Made available in DSpace on 2013-08-22T18:56:03Z (GMT). No. of bitstreams: 1 S0102-09352008000200013.pdf: 136079 bytes, checksum: 2b521c39e7e5a88a9047496f4f8dbb79 (MD5) Previous issue date: 2008-04-01 Made available in DSpace on 2013-09-30T19:49:33Z (GMT). No. of bitstreams: 2 S0102-09352008000200013.pdf: 136079 bytes, checksum: 2b521c39e7e5a88a9047496f4f8dbb79 (MD5) S0102-09352008000200013.pdf.txt: 8995 bytes, checksum: be848545575334885aae1315e71e25d1 (MD5) Previous issue date: 2008-04-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:39:00Z No. of bitstreams: 2 S0102-09352008000200013.pdf: 136079 bytes, checksum: 2b521c39e7e5a88a9047496f4f8dbb79 (MD5) S0102-09352008000200013.pdf.txt: 8995 bytes, checksum: be848545575334885aae1315e71e25d1 (MD5) Made available in DSpace on 2014-05-20T13:39:00Z (GMT). No. of bitstreams: 2 S0102-09352008000200013.pdf: 136079 bytes, checksum: 2b521c39e7e5a88a9047496f4f8dbb79 (MD5) S0102-09352008000200013.pdf.txt: 8995 bytes, checksum: be848545575334885aae1315e71e25d1 (MD5) Previous issue date: 2008-04-01 Avaliou-se a espessura corneana central de 13 gatos normais com microscópio especular de não-contato Topcon SP-2000P e paquímetro ultra-sônico. Foi observado aumento da espessura corneana mensurada pelo paquímetro ultra-sônico comparado ao microscópio especular. The central corneal thickness of 13 normal cats was evaluated by a Topcon SP-2000P noncontact specular microscope and by an ultrasonic pachymetry was evaluated. An increase on the corneal thickness measured by ultrasonic pachymetry as compared to the specular microscope was observed. UNESP Faculdade de Medicina Veterinária e Zootecnia UNESP Faculdade de Medicina Veterinária e Zootecnia

International audience; Cutting-edge medical techniques, of which medical imaging is a keystone, are intimately linked to social representations of the body. How today can we consider body image without taking into account the influence of medical advances in this field ? Our everyday vocabulary is steeped in medical language and clinical practice shows the far-reaching effects of this. The history of medicine bears witness to the successive constructions which have modified social representations of the body. Central to this process is our gaze. With medical imaging, medicine’s gaze has become inherently technological. Psychoanalysis can help shed light on the lifting of repression that the gaze triggers as it beholds a medical image, producing quite different effects in the patient and the doctor. What can the subject’s encounter with such images tell us ? In this virtual realm where our very existence is at stake, clinical practice can enlighten us to the psychic effects of images of the body, precisely because the medical context in which they are discovered deals the subject an extreme experience of them. Exploration of these questions invites us to use our eyes in a more meaningful way and reinstate the gap from whence the subject emerges.; La médecine technoscientifique, avec l’imagerie médicale, s’implique dans les représentations du corps qui circulent dans le social. Comment penser l’image du corps aujourd’hui, sans être à l’écoute de ce que produit cette influence ? Le vocabulaire contemporain du corps est imprégné de médecine, la clinique permet d’en révéler les effets. L’histoire de la médecine témoigne de constructions successives qui modifient la représentation du corps dans le social. Ce processus est centré sur l’importance accordée au regard. Avec l’imagerie, le regard médical devient technologique. L’enjeu d’une investigation psychanalytique de cette problématique consiste en la levée du refoulement que le regard posé sur l’image médicale induit de façon différente chez le patient et le médecin. Ainsi, que donne à entendre la rencontre d’un sujet avec ces images ? Dans ce virtuel du corps où se joue nos existences, la clinique nous renseigne sur les enjeux psychiques des images du corps, précisément car le contexte médical engage le sujet dans une expérience extrême avec ces images. Se pencher sur ces questions invite à faire l’expérience d’un véritable regard qui restitue l’écart d’où le sujet procède.

International audience; The fact of restoring medical imaging in a virtual dimension interrogate about ethics. Within those technical plans, the consequences of image are frequently obscured by the medical investigation as such. Therefore by enquiring about his power, what is at stake through the various observation on it, the ethical interrogation can be spread out as a meeting. Considering technical procedures that allow a reconstitution of the body through an image, correlatively, the patient’s body is bared through the tech- noscientific composition. Transparency fantasies and specular disorders are present in that field where look never meets. Technical medical progress should not be the time for a regression on another therapeutic point of view. The use of a certain technology implies that the question of sufficiency and its applications remains open. Thinking about the background while raising up the repression that it stired up would proba- bly open the way for other therapeutic way where the plurality of look will have enough time to spread out. Having the same look will be the occasion of a meeting with a true ethical character.; Resituer l’imagerie médicale dans la dimension virtuelle dont elle procède invite à déplacer le questionnement éthique sur celle-ci. Les effets de l’image, au centre de ces dispositifs techniques, sont bien souvent occultés par l’investigation médicale comme telle. C’est donc à interroger son pouvoir, mais aussi, à penser ce qui est en jeu dans la multitude des regards posés sur elle, que la question éthique peut se déployer comme rencontre. Aussi, prendre acte des procédés techniques qui rendent possibles l’image recomposant un corps, c’est corrélativement s’inquiéter du sujet du corps qui est mis à nu dans cette recomposition technoscientifique. Fantasmes de la transpa- rence et troubles spéculaires sont en jeu dans cette clinique où les regards ne se rencontrent pas. Les progrès de la médecine technicienne ne devraient pas être l’occasion d’une régression sur un autre plan du thérapeutique. L’utilisation d’une technologie laisse ouverte la question de l’exhaustivité de son application et en penser le contexte en levant le refoulement qu’elle occasionne pourrait bien ouvrir d’autres voies théra- peutiques où le multiple et la pluralité des regards auraient le temps de se déployer. Voir ensemble serait alors l’occasion d’une rencontre à l’enjeu véritablement éthique.

This thesis assessed the readability of CRT displays viewed under ambient lighting conditions and then evaluated the findings with respect to the ISO 9241-7 standard. More specifically, two phases of work were conducted in this thesis. In Phase 1, seven monitors were evaluated photometrically according to the ISO 9241-7 standard to determine whether they were Class I, II, or III in positive and negative polarity. Additionally, six filters were attached to each of the monitors and their ISO Class also was assessed. All monitor/filter combinations yielded either Class I or II in positive polarity and Class II, III or failed in negative polarity. In Phase 2, fourteen participants were asked to read Tinker passages from seven display/filter combinations (tested in Phase 1) under five lighting conditions and two screen polarities. The purpose of the Phase 2 was to determine if people perform differently for Class I, II, or III monitor/filter combinations. The dependent measures were the time to read the Tinker passage (reading time) and the ability to identify the out of context word in each passage (accuracy). An Analysis of Variance was used to determine the significant effects of reading time and accuracy. The ANOVA results indicate that specular glare interferes significantly more with reading time than does diffuse glare. Diffuse (200 lux) and Specular reading times also were correlated against two ISO metrics: screen image luminance ratio (Diffuse, 200 lux) and specular reflection luminance ratio. Reading times did not correlate with the screen image luminance ratio, but they did correlate with one of the ISO specular reflection luminance ratios. The results of this thesis indicate that the ISO standard should not equally weight the screen image and the specular reflection luminance ratios. Additionally, the results indicate that it is not necessary to have separate ISO Classes for positive and negative polarity. Furthermore, people did not read differently for Class I, II, or III monitor/filter combinations. Finally, the data of this investigation provide an initial human factors database for use in assessing the validity of ISO 9241-7. Master of Science

A obra de Michelangelo Pistoletto expõe a própria ideia de espelho, propondo ao mesmo tempo dispositivos especulares no seu trabalho e um meta-discurso sobre a arte enquanto espelho. O seu trabalho conduziu-nos a pensar sobre outras situações de arte contemporânea, ou apenas artísticas em geral. Que reflectem as obras? Como é que reflectem? Apercebemo-nos rapidamente de que a qualidade de “reflectir” no seu duplo sentido, é reconduzível a uma só, por entre tantas outras qualidades dos espelhos e das obras como espelho. Torna-se então necessário substituir aquelas duas perguntas por duas outras: o que fazem as obras quando funcionam como espelhos? E como é que o fazem? Para além de “reflectir” (em francês seriam duas palavras diferentes: “refléter” e “réfléchir”) e para além da sua qualidade reflectora, dão-nos a ver outras qualidades: mnésicas, simbólicas, narrativas, geométricas, algébricas, interpeladoras, reveladoras, auto-reflexivas e meta-discursivas. Chamámos a esse conjunto qualidades especulares das obras (“qualités miroiriques”: em francês o termo é pedido de empréstimo a Duchamp): qualidades do espelho, todas elas. Analisámos o seu funcionamento nas obras, com o auxílio das de Pistoletto e mantendo a preocupação de as pensar a partir de um observador que delas usufrui. A metáfora corrente que pretende que a arte reflecte a vida guiou-nos na convicção de que um objecto ou uma experiência artística só existem para o receptor quando lhes reenviam imagens e possibilidades de si mesmo e do seu mundo; de que a experiência do duplo é menos uma experiência de reprodução do que uma experiência que o alimenta de si próprio. As múltiplas qualidades especulares das obras equivalem ao seu potencial mobilizador; elas conduziram-nos a procurar as formas de vitalidade que se desenham no interior dessa mobilização; ou seja, a retomar o debate, que pareceria esgotado, sobre as relações entre a arte e a vida. Um debate que só nos interessou na medida em que o ponto de vista das qualidades especulares desloca o seu paradigma dual: aquele em que se perfilam as oposições viciadas subjectivo / objectivo, expressionismo / inexpressionismo, expressão / empenho social, contemplação / participação, coisas / imagens, bidimensional / tridimensional, autonomia / utilidade, formalista / referencial, e outras próximas destas. Não há arte em que a vida não esteja inscrita. O que varia são os pontos de vista, as leituras e o tipo de “vida” que se procura ou se denega nela. A obra de Pistoletto fornece-nos exemplos eloquentes. A selecção que fizemos inclui obras tão díspares como objectos, acções ou textos escritos. A sua obra escrita é informativa, literária, programática e plástica, o que não deixa de colocar alguns problemas à abordagem interpretativa. As revelações trazidas pelos seus espelhos literais e metafóricos remetem ainda para as questões da moldura, da pintura, da representação, do sujeito, do auto-reconhecimento e da participação na obra. L’œuvre de Michelangelo Pistoletto expose l’idée même de miroir, en proposant à la fois des dispositifs miroiriques dans son travail et un méta discours sur l’art en tant que miroir. J'ai cru y trouver l’occasion de me poser des questions sur son œuvre qui peuvent peut-être servir à penser d'autres situations d'art contemporain, ou d'art tout court. Que reflètent les œuvres? Comment le reflètent-elles? En essayant de répondre à ces deux questions, on s'aperçoit vite que la qualité de refléter ou de réfléchir n'en est qu'une, parmi d'autres qualités des miroirs, et des œuvres en tant que miroirs. Il faut alors remplacer ces questions par deux autres: Que font les œuvres quand elles fonctionnent comme des miroirs? Et comment? Ce qu'elles font, outre réfléchir et refléter, outre leur qualité réfléchissante, nous montre leurs autres qualités: mnésiques, symboliques, narratives, géométriques, algébriques, interpellatrices, révélatrices, auto réflexives et méta-discursives. J'aimerais appeler cet ensemble « les qualités miroiriques», pour emprunter un terme à Duchamp , puisqu' elles concernent les qualités du miroir. J'ai cru pouvoir analyser leur fonctionnement dans les œuvres, à l’appui de celles de Pistoletto, et en gardant le souci de les rapporter à un récepteur qui en jouit. Je suis donc allée à la recherche de cette métaphore courante qui prétend que l’art reflète la vie dans la conviction qu'un objet ou une expérience artistiques n'existent pour ce récepteur que quand ils lui renvoient des images et des possibilités de lui-même et de son monde; et ceci dans la conviction que, par exemple, son expérience du double est moins une expérience de reproduction qu'une expérience qui le nourrit de lui-même. Les qualités miroiriques multiples des œuvres équivalent à leur potentiel mobilisateur; elles m'ont amenée à rechercher les formes de vitalité qui se dessinent à l’intérieur de cette mobilisation. Autrement dit, à reprendre le débat, qui semblerait plutôt épuisé, sur les rapports entre l’art et la vie. Mais ce débat n'a pu m'intéresser que dans la mesure où le point de vue des qualités miroiriques déplaçait son paradigme duel: celui sur lequel se profilent des oppositions vicieuses comme subjectif/objectif, expressionnisme / inexpressionnisme, expression / engagement social, contemplation / participation, choses / images, bidimensionnel / tridimensionnel, autonomie / utilité, formaliste / référentiel et d'autres qui leur sont proches. Il n'y a pas d'art ou la vie ne soit pas inscrite; ce qui change sont les points de vue, les lectures et le genre de «vie» recherchée et / ou oblitérée. Comme on le verra, c'est encore l’œuvre de Pistoletto qui m'en a fourni les meilleurs prétextes. Celle-ci inclut des initiatives aussi disparates que des objets, des «actions» ou des textes écrits. Son œuvre écrite est à la fois informative, littéraire, programmatique et plastique, ce qui ne va pas sans poser quelques problèmes dans l’approche interprétative. Les révélations apportées par les miroirs littéraux et métaphoriques concernent aussi, entre autres, les problèmes de l’encadrement, de la peinture, de la représentation, du sujet, de l’auto-reconnaissance et de la participation à l’œuvre.

Optical specular reflection is finding extensive use for studies of electrode-electrolyte interfaces. The purpose of this Note is to call attention to the use of complex plane analysis to obtain kinetic information concerning adsorption-desorption processes from the real and imaginary components of p as functions of the ac frequency.