Orientation to the sun by animals and its interaction with crypsis

1. Orientation with respect to the sun has been observed in a wide range of species and hasgenerally been interpreted in terms of thermoregulation and/or ultraviolet (UV) protection. For countershaded animals, orientation with respect to the sun may also result from the pres-sure to exploit the gradient of coloration optimally to enhance crypsis.2. Here, we use computational modelling to predict the optimal countershading pattern for anoriented body. We assess how camouflage performance declines as orientation varies using acomputational model that incorporates realistic lighting environments.3. Once an optimal countershading pattern for crypsis has been chosen, we determineseparately how UV protection/irradiation and solar thermal inflow fluctuate with orientation.4. We show that body orientations that could optimally use countershading to enhance crypsisare very similar to those that allow optimal solar heat inflow and UV protection.5. Our findings suggest that crypsis has been overlooked as a selective pressure on orientationand that new experiments should be designed to tease apart the respective roles of these different selective pressures. We propose potential experiments that could achieve this

Patterns in surface distribution of human exposure to solar ultraviolet

[Abstract]: A method for the three dimensional representation of erythemally effective ultraviolet radiation (UVery) incident to the human body has been developed from a series of polysulphone dosimeter (PS) measurements to the face, neck, arms, legs and hands of a manikin model. The technique has been used to represent a series of human UVery exposure patterns in the solar zenith angle (SZA) range 30o-50o measured in an open environment in Toowoomba, Australia (27.5oS 151.9oE). The human body representations of exposure presented here improve upon existing techniques to represent the UVery exposure to complex body shape topography, providing for the first time, estimates of exposure that take whole body shading effects into account from high density PS dosimeter measurements

Biophilic and photobiological developments of adaptive high-performance building envelopes for Northern Canada

Les configurations des enveloppes et des fenêtres des bâtiments nordiques doivent répondre aux exigences du bien-être photobiologique et psychologique des occupants par des relations positives efficaces avec la nature subarctique. Les enveloppes de bâtiments existant dans les climats (sub)arctiques du nord du Canada n'ont pas encore permis d'établir des connexions efficaces entre l'intérieur et l'extérieur afin d'aborder les relations positives entre les humains et la nature et le bien-être photobiologique et psychologique. Des connexions intérieures-extérieures efficaces indiquent une connectivité optimale de l'intérieur avec la nature subarctique extérieure répondant au bien-être des occupants et aux besoins énergétiques. Les relations positives des occupants avec la nature subarctique correspondent à des avantages maximums et des risques minimums des climats nordiques extrêmes pour le bien-être photobiologique-psychologique. L'objectif général de cette thèse est de favoriser les relations positives des occupants avec la nature subarctique au moyen de connexions efficaces entre l'intérieur et l'extérieur qui pourraient répondre aux facteurs de bien-être biophiliques et photobiologiques liés à la lumière du jour et aux photopériodes. Dans ce but, un modèle fondamental d'enveloppe de bâtiment adaptative à haute performance est développé comme une solution architecturale qui pourrait optimiser les connexions intérieur-extérieur et les principaux indicateurs biophiliques et photobiologiques. La thèse visait spécifiquement à articuler une approche photobiologique du design biophilique dans les climats nordiques extrêmes qui permet d'établir un cadre conceptuel et de design pour développer des enveloppes de bâtiments. La thèse visait également à identifier les lacunes des enveloppes de bâtiment existantes dans le Grand Nord du Canada ainsi que des systèmes d'enveloppes adaptatives existants en termes d'indicateurs biophysiques-photobiologiques. Les principaux éléments architecturaux des enveloppes adaptatives, notamment la configuration des fenêtres et les caractéristiques de surface des systèmes d'ombrage, en particulier la couleur et la réflectance, sont étudiés pour répondre aux besoins biophiles-photobiologiques des occupants du Nord. Les méthodologies de la thèse comprennent une revue de la littérature pour discuter des directives récentes de design biophilique, de l'éclairage photobiologique et des études de connectivité avec la nature par rapport aux climats subarctiques, en particulier la lumière du jour et les photopériodes. Des méthodes numériques et expérimentales ont été intégrées pour évaluer les performances biophiliques, d'éclairage photobiologique, thermiques et énergétiques des systèmes d'enveloppe pour une étude de cas d'un bureau open-plan dans le nord du Canada. Des méthodes expérimentales avec des modèles à l'échelle physique, des images à haute gamme dynamique et des techniques de post-traitement ont été utilisées pour capturer, calculer et visualiser les paramètres d'éclairage photobiologique. L'impact des caractéristiques des panneaux d'ombrage (SP) sur les performances d'éclairage photobiologique a été étudié par l'expérimentation d'environ 40 prototypes à l'échelle 1:50 et 23 prototypes à l'échelle 1:10 sous un ciel dégagé/couvert avec un éclairage naturel réel/artificiel. Des modèles numériques ont été développés pour évaluer les caractéristiques biophiques et thermiques/énergétiques des systèmes d'enveloppe. Les résultats de la thèse comprennent un cadre théorico-conceptuel du design photobiologique - biophilique qui identifie les relations positives des occupants avec la nature subarctique à travers les enveloppes. Des scénarios d'adaptation de l'éclairage photobiologique intégrés aux exigences thermiques ont été élaborés, qui permettent de répondre aux besoins photobiologiques horaires/saisonniers des occupants du Nord dans des bâtiments différents. Les lacunes des enveloppes à une peau typique du Nord du Canada et des enveloppes à plusieurs peaux avec des profondeurs d'espaces intermédiaires/cavités et des tailles de fenêtre différentes ont été spécifiquement évaluées en termes des indicateurs biophiliques, photobiologiques et thermiques. Un modèle fondamental d'enveloppes adaptatives à haute performance est proposé pour les bâtiments du Nord, qui comprend une taille de fenêtre optimale, un système d'ombrage dynamique coloré et isolé, et un système de buffer thermique constitué d'une peau extérieure en verre. Les performances d'éclairage photobiologique des configurations des SP, incluant la couleur, la réflectance, l'orientation, l'inclinaison, la densité, la taille, l'ouverture et la position à la fenêtre, ont été caractérisées. Les résultats des élévations expérimentales/numériques montrent que l'enveloppe adaptative proposée pourrait offrir des connexions intérieures-extérieures efficaces qui répondent aux besoins photobiologiques-psychologiques et aux exigences énergétiques des occupants du Nord. Les résultats de la thèse pourraient informer les architectes et les responsables politiques sur les possibilités que les enveloppes adaptatives et les cadres photobiologiques-biophiles offrent pour améliorer le bienêtre du public et l'efficacité énergétique dans les climats nordiques. Les principaux enjeux des futurs développements des bâtiments biophiliques adaptatifs dans les climats nordiques ont également été soulignés, notamment en matière d'analyses du cycle de vie et d'études socioculturelles.Sub-Arctic building envelope configurations must address occupants' photobiological-psychological wellbeing through positive relationships with the outdoor sub-Arctic nature. Existing building envelopes in Northern Canada's (sub-)Arctic climates have not, yet, enabled efficient indoor-outdoor connections to address positive human-nature relationships and photobiological-psychological wellbeing. Efficient indoor-outdoor connections indicate optimum connectivity of indoors with Northern climates in terms of occupants' wellbeing and energy factors. Positive occupants' relationships with the sub-Arctic nature refer to maximum benefits and minimum risks of the extreme cold weather and strong photoperiod of Northern climates for photo-biological and psychological wellbeing. The general objective of this dissertation is to foster positive occupants' relationships with sub-Arctic nature by enabling efficient indoor-outdoor connections which could respond to biophilic and photobiological wellbeing factors related to daylighting and photoperiods. To this end, a fundamental model of adaptive high-performance building envelopes is developed as an architectural solution which could optimize indoor-outdoor connections and main biophilic and photobiological indicators. The dissertation specifically aimed at articulating a photobiological approach to biophilic design in extreme Northern climates which enables establishing a conceptual and design framework to develop building envelopes. The thesis also focused on identifying the shortcomings of existing Canadian Northern building envelopes as well as existing adaptive envelope systems in terms of biophilicphotobiological indicators. Main architectural elements of adaptive envelopes including window configuration and surface characteristics of shading systems, in particular color and reflectance, are explored to respond to Northern occupants' biophilic-photobiological needs. The thesis methodologies include a scoping literature review to critically discuss recent biophilic design guidelines, photobiological lighting, and nature connectedness/relatedness studies in relation to sub-Arctic climates, especially daylighting and photoperiods. Numerical and experimental methods were integrated to evaluate biophilic, photobiological lighting, thermal and energy performance of envelope systems for a case study of an open-plan office in Northern Canada. Experimental methods with physical scale models, high dynamic range imagery and post-processing techniques were employed to capture, compute, and visualize photobiological lighting parameters. Impacts of shading panels' (SPs) characteristics on photobiological lighting performance were explored by experimenting approximately 40 1:50-scale prototypes and 23 1:10-scale prototypes under clear/overcast skies with actual/artificial daylighting. Numerical models were developed to evaluate biophilic and thermal/energy performance of envelope systems. Dissertation outcomes include a theoretical-conceptual framework of photobiological-biophilic design which characterizes positive occupants' relationships with the sub-Arctic nature through envelopes. Photobiological lighting adaptation scenarios integrated with thermal requirements were developed which could address hourly/seasonal photobiological needs of Northern occupants in different buildings. Deficiencies of typical single-skin envelopes in Northern Canada and multi-skin envelopes with different depths of intermediate spaces/cavities and window sizes were specifically evaluated in terms of biophilic, photobiological lighting and thermal indicators. A fundamental model of adaptive high-performance envelopes is proposed for Northern buildings which includes an optimum window size, a dynamic-colored-insulated shading system, and a thermal buffer system made of a glazing exterior skin. Photobiological lighting performance of SPs' configurations, including color, reflectance, orientation, inclination, density, size, openness, and position at the window, were characterized. Results of experimental-numerical elevations reveal that the proposed adaptive envelope could offer efficient indoor-outdoor connections which respond to Northern occupants' photobiological-psychological needs and energy requirements. Dissertation outcomes could enlighten architects and policymakers about potentials of adaptive envelopes and integrative photobiological-biophilic frameworks to improve public wellbeing and energy efficiency in Northern climates. Major issues for future developments of adaptive biophilic buildings in Northern climates were also outlined including life cycle assessments and sociocultural studies

Self-supervised Multi-level Face Model Learning for Monocular Reconstruction at over 250 Hz

The reconstruction of dense 3D models of face geometry and appearance from a single image is highly challenging and ill-posed. To constrain the problem, many approaches rely on strong priors, such as parametric face models learned from limited 3D scan data. However, prior models restrict generalization of the true diversity in facial geometry, skin reflectance and illumination. To alleviate this problem, we present the first approach that jointly learns 1) a regressor for face shape, expression, reflectance and illumination on the basis of 2) a concurrently learned parametric face model. Our multi-level face model combines the advantage of 3D Morphable Models for regularization with the out-of-space generalization of a learned corrective space. We train end-to-end on in-the-wild images without dense annotations by fusing a convolutional encoder with a differentiable expert-designed renderer and a self-supervised training loss, both defined at multiple detail levels. Our approach compares favorably to the state-of-the-art in terms of reconstruction quality, better generalizes to real world faces, and runs at over 250 Hz.Comment: CVPR 2018 (Oral). Project webpage: https://gvv.mpi-inf.mpg.de/projects/FML

A site-specific standard for comparing dynamic solar ultraviolet protection characteristics of established tree canopies

A standardised procedure for making fair and comparable assessments of the ultraviolet protection of an established tree canopy that takes into account canopy movement and the changing position of the sun is presented for use by government, planning, and environmental health authorities. The technique utilises video image capture and replaces the need for measurement by ultraviolet radiometers for surveying shade quality characteristics of trees growing in public parks, playgrounds and urban settings. The technique improves upon tree shade assessments that may be based upon single measurements of the ultraviolet irradiance observed from a fixed point of view. The presented technique demonstrates how intelligent shade audits can be conducted without the need for specialist equipment, enabling the calculation of the Shade Protection Index (SPI) and Ultraviolet Protection Factor (UPF) for any discreet time interval and over a full calendar year

Personal solar UV exposure measurements employing modified polysulphone with an extended dynamic range

Polysulphone dosimeters using a simple to use filter have been developed and tested to provide an extended dynamic measurement range of personal solar UV exposures over an extended period (3 to 6 days). At a Southern Hemisphere subtropical site (27.68S, 151.98E), the dynamic range of the filtered polysulphone allowed measurements of erythemal exposures to approximately 100 minimum erythemal dose (MED) for a change in optical absorbance at 330 nm (DA330) of 0.35. In comparison, unfiltered polysulphone dosimeters were exposed to approximately 8 MED for the same DA330. The error associated with the use of the filtered polysulphone dosimeters is of the order of 615%, compared with 610% of the unfiltered variety. The developed filtered polysulphone dosimeter system allowed the measurement of erythemal UV exposures over 3 to 6 days at a subtropical site without the need to replace the dosimeters because of saturation. The results show that longer-term measurement programs of personal solar UV have been made more feasible with the use of these polysulphone dosimeters with an extended dynamic range compared with unfiltered polysulphone dosimeters

Optical techniques for 3D surface reconstruction in computer-assisted laparoscopic surgery

One of the main challenges for computer-assisted surgery (CAS) is to determine the intra-opera- tive morphology and motion of soft-tissues. This information is prerequisite to the registration of multi-modal patient-specific data for enhancing the surgeon’s navigation capabilites by observ- ing beyond exposed tissue surfaces and for providing intelligent control of robotic-assisted in- struments. In minimally invasive surgery (MIS), optical techniques are an increasingly attractive approach for in vivo 3D reconstruction of the soft-tissue surface geometry. This paper reviews the state-of-the-art methods for optical intra-operative 3D reconstruction in laparoscopic surgery and discusses the technical challenges and future perspectives towards clinical translation. With the recent paradigm shift of surgical practice towards MIS and new developments in 3D opti- cal imaging, this is a timely discussion about technologies that could facilitate complex CAS procedures in dynamic and deformable anatomical regions