Notre environnement visuel est riche en lumière, couleurs, traits, textures et formes. Pour appréhender cette richesse, nous déplaçons nos yeux tous les quarts de seconde à l'aide de mouvements très rapides appelés saccades. Une telle vision dite active a fait l’objet de multiples recherches, mais les interactions entre les systèmes visuel et oculomoteur ne sont pas clairement établies. Cette thèse vise à préciser ces interactions en étudiant si les délais temporels associés au traitement d'informations visuelles de plus en plus élaborées contraignent où et quand nos yeux bougent. Trois séries d'études comportementales menées chez l'homme et utilisant des paradigmes novateurs ont été réalisées. Elles nous ont permis de mettre en évidence que le traitement des contrastes d'orientation, tout comme le traitement des contrastes de luminance sont intégrés par le système saccadique. En effet, un stimulus (distracteur) différant d'un fond texturé par sa luminance ou son orientation dévie le regard de sa cible dans la même mesure, et ce, quelle que soit la latence des saccades. Néanmoins, le contraste de luminance conserve un rôle prédominant. Premièrement, il conduit au déclenchement plus précoce des saccades en comparaison avec le contraste d’orientation. Deuxièmement, dès lors qu'il entre en compétition avec des informations plus élaborées comme le contour, il suffit à déterminer la métrique des saccades. Ainsi, en accord avec l'architecture des systèmes visuel et oculomoteur, les traitements visuels influencent la programmation des saccades de manière ordonnée. / Our environment is rich in light, color, features, textures, and shapes. To extract this information, we move our eyes four times per second with rapid eye movements called saccades. This so-called active vision has been studied extensively, but the interactions between the visual and oculomotor systems have not been fully characterized yet. This thesis aims to clarify these interactions by investigating whether the delays in processing visual information of increasing complexity determine where and when our eyes move. The present work focuses on three types of basic visual processing for which the neural substrates are well established and predict a specific order in the programming of saccades at the level of the superior colliculus. We conducted three series of behavioral studies with human participants using novel experimental paradigms. These studies showed that orientation-contrast processing as well as early luminance-contrast processing are integrated in the saccadic system to the same extent. When aiming for a target stimulus, the eyes deviate toward a distractor stimulus in equal measure, irrespective of whether the distractor differed in luminance or orientation from a texture background and irrespective of saccade latency. However, the role of luminance contrast remains dominant. Firstly, luminance contrast triggers faster saccades than orientation contrast. Secondly, when luminance contrast competes with more complex information such as contour, solely luminance contrast determines saccade metrics. Therefore, visual processes influence saccade programming in a specific order that is consistent with the architecture of the visual and oculomotor systems.

This master's thesis deals with the search of commercially available luminance analysers and cameras that use the measurement of correlated colour temperature. It also deals with calculations of correlated colour temperature according to various available methods. The luminance analyser LDA-LumiDISP is based on a DSLR camera. The principle of its operation and possible errors in capturing pictures are discussed here. The work deals with extensive testing of the LDA-LumiDISP luminance analyser, which is primarily intended for measuring luminance in the set scene, but can also be used to measure the correlated colour temperature. The device is being tested in terms of measuring the correlated colour temperature in laboratory and field conditions. The result of the master's thesis is the calculation of measurements uncertainty for certain light sources and the optimization of the measuring algorithm to reduce them.

<p>Over the last two decades, an increasing number of highway construction and maintenance projects in the United States have been completed at night to avoid or mitigate traffic congestion delays. Working at night entails several advantages, including lower traffic volumes at night, reduced impact on local businesses, more freedom for lane closures, longer possible work hours, lower pollution, cooler temperatures for equipment and material, and fewer overall crashes due to lower traffic volumes at night. Although nighttime roadway operations may minimize traffic disruptions, there are several safety concerns for motorists passing by and for workers in the nighttime work zone. For instance, just in 2019, there were 842 work zone fatalities reported in the United States, with 48% of these being associated with fatalities on night shifts. Additionally, 70% of these fatalities involved drivers/occupants under the age of 50. Moreover, improper lighting arrangements or excessive lighting levels produced by temporary lighting systems installed at the job site could cause harmful levels of glare for the traveling public and workers leading to an increase level of hazards and crashes in the vicinity of the work zone. </p> <p>To address the issue of glare, very few studies have been conducted to evaluate and quantify glare at work zones. Most of these studies were limited to the determination of disability glare levels of lighting systems (balloon lights and light towers) with a metal-halide type light source by using the veiling luminance ratio (<em>VL ratio</em>) as a criterion for limiting disability glare. However, deeper evaluation of the effects of driver’s age on the veiling luminance ratio, and the use of energy-efficient lighting systems which employ light-emitting diode (LED) type light sources were not performed.</p> <p>This thesis focuses on determining and evaluating disability glare on nighttime work zones as a step towards developing appropriate lighting strategies for improving the safety of workers and motorists during nighttime highway construction and maintenance projects. Disability glare is the glare that impairs our vision of objects without necessarily causing discomfort and it can be evaluated using the veiling luminance ratio (<em>VL ratio</em>). In this study, disability glare values were determined by using lighting data (vertical illuminance and pavement luminance measurements) from testing 49 lighting arrangements. Two LED balloon lights, a metal-halide light tower, and an LED light tower were utilized for the field lighting experiments. The disability glare level evaluation examines the effects of mounting height, power output, rotation angle, and aiming angle of luminaires on the veiling luminance ratio values (which is a criterion for limiting disability glare). </p> <p>The analysis of the disability glare values revealed four major findings regarding the roles played by the mounting height, power output, lighting system orientation, aiming angles of luminaries, and driver’s age on disability glare levels as follows: (i) an increase in mounting heights of both balloon lights and light towers resulted in lower veiling luminance ratio values (or disability glare); (ii) compared to the "perpendicular" and "away" orientations, orienting the light towers in a "towards" direction (45 degrees) significantly increases the disability glare levels of the lighting arrangement; (iii) increasing the tilt angles of luminaires of the portable light towers resulted in an increase in veiling luminance ratio values; (iv) for balloon lights, at observers ages over 50, <em>VL ratio</em> values were found to be greater than the maximum recommended; (v) for LED light towers oriented towards the traffic, at driver’s ages over 40, <em>VL ratio</em> values exceed the Illuminating Engineering Society (IES) recommended value; and (vi) for metal-halide light towers oriented towards the traffic, at driver’s ages over 50, <em>VL ratio</em> values exceed the IES recommended value. The results from this research study can provide State Transportation Agencies (STAs) and roadway contractors with a means to improve glare control strategies for nighttime work.</p>

Cette étude est basée sur des données multi-altitudes aéroportées acquises en juillet 2004 lors d'un événement atmosphérique inhabituel dans la région de Saint-Jean-sur-Richelieu. Nous entendons en cela une atmosphère dont la distribution des aérosols ne respecte pas les variations habituellement implémentée dans les codes de transfert radiatifs. Les surfaces au sol imagées pendant cette campagne de terrain couvraient une variété spectrale assez diversifiée, à savoir des surfaces agricoles, des plans d'eau et des zones urbaines et forestières. L'aspect multi-altitude de cette acquisition de données a permis de caractériser les mêmes cibles au sol avec des contributions de l'atmosphère variant en fonction de l'altitude considérée afin de caractériser au mieux la perturbation observée durant cette campagne et de permettre une meilleure caractérisation de la perturbation apportée par une variation non-standard (panache de fumée). La transformation de la luminance apparente aux trois altitudes en réflectance apparente et l'implémentation de la perturbation apportée par le panache de fumée dans un modèle classique a permis une correction atmosphérique appliquée aux deux altitudes les plus hautes. Les résultats ont démontré une cohérence avec les réflectances apparentes de validation qui confirmait la véracité de notre modélisation du cas non-standard. Ces résultats ont d'autant plus étés pertinent [i.e. pertinents] pour la plus haute altitude de 3,17km : la réflectance apparente à cette altitude est au dessus de la majeur [i.e. majeure] partie du panache de fumée et intègre une bonne proportion de la perturbation apportée par ce panache, ce qui représente un test probant de notre capacité à corriger adéquatement l'influence de cette perturbation. Les perturbations atmosphériques standard sont évidemment prises en compte dans la majorité des modèles atmosphériques, mais ceux-ci sont souvent basés sur des variations monotones des caractéristiques physiques de l'atmosphère avec l'altitude. Lorsque la radiation atmosphérique est perturbée, par un panache de fumée ou un événement de pollution atmosphérique local et non standard, cela nécessite une modélisation et une modification adéquate des modèles existants en fonction des paramètres que l'on pourra obtenir sur ladite perturbation. Les intrants principaux de cette étude étaient ceux normalement utilisés lors d'une correction atmosphérique classique à savoir les luminances apparentes mesurées par un imageur aéroporté mais à trois altitudes différentes et l'épaisseur optique des aérosols (AOD) qui était acquise depuis le sol. La méthodologie que nous avons employé [i.e. employée] utilise aussi un code de transfert radiatif (CAM5S, pour Canadian Modified 5S, qui vient directement du code de transfert radiatif 5S dans le visible et proche infrarouge). Cependant il nous faudra aussi avoir recours à d'autres paramètres et données afin de modéliser correctement la situation atmosphérique particulière présente sur les images multi-altitude acquises pendant la campagne de terrain à Saint-Jean-sur-Richelieu. Nous avons alors élaboré un protocole de modélisation de perturbation atmosphérique non standard où une gamme de données auxiliaires disponibles est venue compléter nos données principales. Cela a permis l'élaboration d'une méthodologie robuste et relativement simple adaptée à notre problématique. Ces données auxiliaires, à savoir des données météorologiques, des profils LEDAR, différentes images satellites et des données de photomètres solaires qui ont permis la détermination de la fonction de phase des aérosols, ont été suffisantes pour établir une modélisation adéquate du panache de fumée observé en terme de distribution verticale non monotone des paramètres physiques relevés lors de cette campagne. Cette distribution non-standard à été par la suite interprétée en terme de profil spécifique de l'AOD qui a remplacé les profils des AOD employés dans le modèle de correction atmosphérique CAM5S. En fonction de cette modélisation, nous montrons que l'erreur entre les réflectances apparentes au sol obtenu [i.e. obtenue] par le processus de correction atmosphérique et les réflectances apparentes au sol provenant du processus de validation dR*(0), moyenné quadratiquement à travers les bandes visibles, reste majoritairement dans une gamme inférieure à 0,01 d'erreur quadratique moyenne des R*(0) après avoir modélisé la perturbation non-standard, ce qui permet une estimation plus acceptable des réflectances multi-altitude et du biais existant entre la prise en compte et la non prise en compte de cette perturbation dans le modèle atmosphérique. D'importants écarts ont néanmoins été observés, majoritairement attribuables à la difficulté apportée par les conditions d'acquisition, les grandes disparités observées entre l'échantillonnage des mêmes surfaces aux trois altitudes, et probablement des erreurs de modélisation et/ou de calibration. La nécessité d'améliorer le processus d'acquisition, de modélisation et de prévision de telle perturbation est largement décrit dans ce document afin de permettre à l'avenir d'établir un protocole d'acquisition plus adapté grâce notamment à une surveillance et un suivi des perturbations atmosphériques maintenant possible grâce aux outils décrits. L'originalité de cette étude réside dans une nouvelle approche de la caractérisation de ces perturbations atmosphériques par l'incorporation d'une structure non standard dans un modèle de correction atmosphérique opérationnel et de démontrer que cette approche présente des améliorations significatives des résultats par rapport à une approche qui ignore la perturbation du profil vertical standard tout en utilisant des valeurs d'AOD totaux correctement mesurés. Le modèle de profil que nous avons employé était simple et robuste, mais a capturé suffisamment de caractéristiques du panache pour réaliser des améliorations significatives en termes de précision de correction atmosphérique. Le processus global d'aborder tous les problèmes rencontrés dans l'analyse de notre perturbation des aérosols nous a aidé à construire une méthodologie appropriée pour caractériser ces événements sur la base de la disponibilité des données, distribué gratuitement et accessibles à la communauté scientifique. Cela rend cette étude adaptable et exportable à d'autres problématiques du même genre.

Detta examensarbete undersöker hur belysningen vid receptionsdiskar faktiskt serut och hur personalen som arbetar där upplever den. Syftet med examensarbetetär att identifiera om det finns anledning att förändra de riktlinjer och rekommendationersom ställs på belysning på och omkring receptionsdiskar. På hotellen idag är oftast miljöerna dämpade och varierande då hotellens syfte äratt skapa en upplevelse för gästerna. Det har väckt ett intresse hos oss att undersökareceptionsdisken som är en viktig plats på hotellen. Vi har jämfört ”Ljus ochRums” rekommendationer (SIS, 2011) med faktiskt uppmätta ljusnivåer i fyra receptionsdiskaroch personalens upplevelse av hur det påverkar hur de kan utförasina dagliga arbetsuppgifter. De metoder vi har använt är ljusmätning, jämnhetsberäkning, visuell analys ochenkätundersökning. Ljusmätningarna utfördes på fyra olika hotell i Göteborg.Frågeformuläret vände sig till personalen på hotellen och handlade om deras upplevelseav ljuset på och omkring receptionsdisken. För att få en uppfattning ochövergripande förståelse utfördes en visuell analys på hotellen. Majoritet av personalen anser att belysningen var tillräcklig för att utföra sina arbetsuppgifter.Det är tydligt att ljuset uppfattas olika på de fyra receptionsdiskarnaberoende på hur hotellet är utformat och designat. / The purpose of this study is to identify if there is reason to change the requirementsand recommendations for illumination in reception desks areas. This studyexamines how lighting in reception desks areas actually is and how the staff perceivesthe lighting. Hotels today usually have subdued environments that vary according to the typeof experience intended for their guests. Our interest has been to explore the receptiondesks area as an important and separate element within the hotel. We havecompared “Ljus och Rum” recommendations (Swedish Standards Institute [SIS],2011) with actual measured light levels for four reception desks areas and examinedhow the staff perceives how the lighting affects their performance of dailytasks. The methods we have used are light measurement, evenness calculations, visualanalysis and surveys. Lighting measurements were performed at four differenthotels in Gothenburg. The questionnaire was directed to the hotel staff in order toascertain their perception of the lighting in and around the reception’s desks area.In order to get an impression of and gain an overall understanding for the lighting,a visual analysis was done at each hotel. The majority of the staff considers the lighting sufficient to perform their duties.It is clear that the lighting is perceived differently in each of the four hotels, dependingon how each hotel is formed and how the lighting is designed.

Inter-ocular suppression occurs when very different images are presented to each eye. Diplopia ensues if different images are superimposed and perceived. The brain removes this unfavourable viewing experience by suppressing one eye’s input to enable clear single vision. Inter-ocular suppression during visual development occurs in response to sufficiently disparate images caused by strabismus (misalignment of the visual axis) or anisometropia (uncorrected difference in refractive error), and if persistent may result in amblyopia. This is reduced visual sensitivity, usually in one eye, to a range of visual functions that cannot be corrected by refraction. Furthermore, binocular vision is reduced or absent. Depth and extent of suppression is measured across the central visual field in healthy participants with monocularly blurred vision, healthy participants with monocularly reduced luminance using neutral density (ND) filters, and participants with naturally disrupted binocular vision and/or amblyopia. Suppression of spatial stimuli defined by luminance (L) and luminancemodulated noise (LM) was compared to that measured for stimuli defined by contrast-modulated noise (CM), for which there is no change in mean luminance. For all stimuli suppression depth increased with increased imbalance of binocular input. Suppression was of a similar depth across the visual field with imposed blur and localised central suppression was found with ND filters. Microstrabismics showed central suppression, while strabismic amblyopes showed central in addition to hemifield suppression. Suppression for all participants was measured to be deeper for CM spatial stimuli than for LM spatial stimuli. This is suggested to be a result of CM stimuli engaging more binocular mechanisms of processing, than LM stimuli, thereby becoming more sensitive to disruptions of binocularity such as those produced in the participants in the present study. CM stimuli are therefore more sensitive to detecting suppression, which is associated with amblyopia.

Made available in DSpace on 2017-07-10T15:14:24Z (GMT). No. of bitstreams: 1 DissertacaoKarisonPan.pdf: 1015309 bytes, checksum: 93e2e670b8d0848a1a6d263fde610ff5 (MD5) Previous issue date: 2015-03-06 / In broiler production systems the use of lighting programs proper is a factor that directly influences the welfare and birds productivity. The objective of this study was to evaluate two artificial lighting systems used in broiler poultry house, as to its allocative efficiency of luminance. The study was conducted in Iporã Pr. Evaluated the lighting of two aviaries with different lighting and building systems. One barn was closure with conventional system of black raffia bag (dark house), not being thermally insulated (N.ISO) and its lighting system consisted of incandescent bulbs, compact fluorescent and LED. The other barn was with extruded polystyrene panel (XPS), and thermally insulated (ISO) and its lighting system was composed entirely of compact fluorescent lamps. Was analyzed the extent of influence of external natural Sunshine, inside the poultry through the exhausts, and the degree of distribution of illumination in the poultry with statistical analysis and study of the distribution uniformity coefficient (CUD). Contour maps were produced showing the degree of internal luminance distribution for each set of lamp technology, in the area that did not suffer interference of external natural Sunshine. The results showed that the external natural Sunshine influenced the indoor lighting to distance of the second pillar (18m) from the bottom to the front and there was a better luminance uniformity in ISO aviary. / Na criação de frangos de corte o uso adequado de programas de iluminação é um fator que influencia diretamente o bem estar e produtividade das aves. O objetivo deste trabalho foi avaliar dois sistemas de iluminação artificial utilizados em aviários de frango de corte, quanto à sua eficiência distributiva de iluminamento. O trabalho foi realizado no município de Iporã Pr. Avaliou-se a iluminação de dois aviários com sistemas de iluminação e sistemas de construção diferentes. Um dos aviários era fechado com sistema convencional de lona de ráfia escura (dark house), não sendo isolado termicamente (N.ISO) e seu sistema de iluminação era composto por lâmpadas incandescentes, fluorescente compacta e led. O outro aviário era fechado com isopainéis de poliestireno extrudado (XPS), sendo isolado termicamente (ISO) e seu sistema de iluminação era composto somente por lâmpadas fluorescente compacta. Foram analisados o alcance da influência da luz externa do Sol para dentro do aviário, por meio dos exaustores, e o grau de distribuição da iluminação nos aviários por meio de análises estatísticas e do estudo do coeficiente de uniformidade de distribuição (CUD). Foram confeccionados mapas de isolinhas mostrando o grau de distribuição de iluminamento interno para cada conjunto de tecnologia de lâmpada, na área que não sofria interferência da iluminação natural externa do Sol. Os resultados mostraram que a iluminação natural externa do Sol influenciava a iluminação interna até a distância do segundo vão (18m), do fundo para a frente e que houve uma melhor homogeneidade de iluminamento no aviário ISO.

Abstract Purpose: Interocular inhibitory interactions appear to underlie the establishment of ocular dominance. The inhibitory effect leads to suppression of the non dominant eye in certain conditions. While these processes are not fully understood, the relative differences in image contrast appear to be fundamental. By titrating the relative contrast presented to each eye, a balance in the relative inhibitory effects of each eye can be defined. This research looked at whether the interocular contrast ratio at perceptual balance could be used as an index of the ocular dominance in binocular normal population, and the suppression typically found in the amblyopic population. Contrast variation was compared to luminance variation as well as the application of neutral density filters. Methods: Balance point measures were obtained by varying the interocular levels of contrast for a global motion task viewed dichoptically. One eye received signal dots moving in a given direction while the other eye received noise dots moving randomly. Subjects were tasked with determining the direction of movement of the signal dots. Balanced dichoptic motion sensitivity was achieved under a specific contrast ratio (or the balance point), depending on the observer’s binocular functions. This test was conducted on a control group (n=23) having normal vision and a strabismic amblyopic group (n=10). In addition, a variation of this test was designed with interocular luminance (rather than interocular contrast) serving as the independent variable was conducted to both the control (n=5) and amblyopic groups (n=8). Concurrent eye tracking measures measured changes in eye alignment at the balance point. Results: Although most normal vision subjects showed a balance point at close to equal levels of contrast between the eyes, a minority of them were significantly imbalanced. The suppression measured in the strabismic amblyopic group was significantly greater than that of the control group. Varying the interocular luminance instead of contrast failed to affect the coherence motion thresholds. Ocular alignment was not changed when the balance point was reached. Conclusion: Consistent with the current model of binocular integration, interocular contrast are uniquely important in establishing sensory dominance and suppression. This suggests that the interocular suppression found in amblyopia could be attenuated by methods that allow the reduction of contrast to the fellow fixing eye. Amblyopia therapy might then be improved where such contrast balancing methods are employed instead of the complete patching of the fellow eye.

Early studies about territory defense of territorial male butterflies were focused on factors that may affect the outcome of contest. But rapid detection was so critical for territorial defense. The detection ability was correlated to visual system. Studies had focused on visual system such as the structure of eye optics and electrophysiology. However, it still existed one question about how do the owner detect intruder in the field. Some factors may affect the probability of detecting intruders from an owner, such as the distance, the size of the intruder, and background contrast. To determine what factor might affect detection ability of territorial male butterfly Hypolimnas bolina, two different sized butterfly models and four different luminance models were used to determine: 1. The reaction rate of the owner with differrent distances; 2. Test the detection ability at different relative position between intruders and owner (acute zone). 3. To test the visual angle hypothesis; 4. Test the luminance contrast effect. The results showed that the response rate decreased with distance but increased with model size. The owner had greater detection ability when the model was presented in the front rather than it on the side. Finally, the response rate was increased with model¡¦s low luminance. Besides, if the model was darker than its background, the owner¡¦s detection ability was greater. Previous studies indicated that a complex background may let the owner spend more time in detection. However, it was quite different with Hypolimnas bolina. In fact, the owner could quickly detect the model when the model was in a complex background, even there was without luminance contrast between the model and background.

Abstract Purpose: Interocular inhibitory interactions appear to underlie the establishment of ocular dominance. The inhibitory effect leads to suppression of the non dominant eye in certain conditions. While these processes are not fully understood, the relative differences in image contrast appear to be fundamental. By titrating the relative contrast presented to each eye, a balance in the relative inhibitory effects of each eye can be defined. This research looked at whether the interocular contrast ratio at perceptual balance could be used as an index of the ocular dominance in binocular normal population, and the suppression typically found in the amblyopic population. Contrast variation was compared to luminance variation as well as the application of neutral density filters. Methods: Balance point measures were obtained by varying the interocular levels of contrast for a global motion task viewed dichoptically. One eye received signal dots moving in a given direction while the other eye received noise dots moving randomly. Subjects were tasked with determining the direction of movement of the signal dots. Balanced dichoptic motion sensitivity was achieved under a specific contrast ratio (or the balance point), depending on the observer’s binocular functions. This test was conducted on a control group (n=23) having normal vision and a strabismic amblyopic group (n=10). In addition, a variation of this test was designed with interocular luminance (rather than interocular contrast) serving as the independent variable was conducted to both the control (n=5) and amblyopic groups (n=8). Concurrent eye tracking measures measured changes in eye alignment at the balance point. Results: Although most normal vision subjects showed a balance point at close to equal levels of contrast between the eyes, a minority of them were significantly imbalanced. The suppression measured in the strabismic amblyopic group was significantly greater than that of the control group. Varying the interocular luminance instead of contrast failed to affect the coherence motion thresholds. Ocular alignment was not changed when the balance point was reached. Conclusion: Consistent with the current model of binocular integration, interocular contrast are uniquely important in establishing sensory dominance and suppression. This suggests that the interocular suppression found in amblyopia could be attenuated by methods that allow the reduction of contrast to the fellow fixing eye. Amblyopia therapy might then be improved where such contrast balancing methods are employed instead of the complete patching of the fellow eye.