Pair-wise preferential experiments were used to reveal dangerous predator differentiation and ability of amodal completion by four tit species. Firstly was revealed that the tits{\crq} behaviour towards the feeder was in agreement with predictions of the dynamic risk assessment theory. The presence of any predator at the feeder lowered the number of visits to the feeder. Likewise, the tits evaluated the sparrowhawk as more dangerous than the kestrel because its presence lowered the number of visits more than the kestrel. Secondly, we observed tits{\crq} reactions to both partly occluded and amputated dummy of sparrowhawk in two different treatments (torsos vs. complete dummy of pigeon, torsos vs. complete dummy of sparrowhawk). All birds clearly classified both torsos as ``full-featured{\crqq} predators and kept away of them when pigeon on the second feeder. However, when sparrowhawk was presented on the second feeder, number of visits to amputated predator was higher than to occluded one. Birds risked arriving to ``utter{\crqq} amputated torso while the fear of ``full-featured{\crqq} occluded torso stayed without change when second feeder did not provide safe alternative. Such discrimination between torsos needs ability of amodal completion.

Pair-wise preferential experiments were used to reveal dangerous predator differentiation and ability of amodal completion by four tit species. Firstly was revealed that the tits{\crq} behaviour towards the feeder was in agreement with predictions of the dynamic risk assessment theory. The presence of any predator at the feeder lowered the number of visits to the feeder. Likewise, the tits evaluated the sparrowhawk as more dangerous than the kestrel because its presence lowered the number of visits more than the kestrel. Secondly, we observed tits{\crq} reactions to both partly occluded and amputated dummy of sparrowhawk in two different treatments (torsos vs. complete dummy of pigeon, torsos vs. complete dummy of sparrowhawk). All birds clearly classified both torsos as ``full-featured{\crqq} predators and kept away of them when pigeon on the second feeder. However, when sparrowhawk was presented on the second feeder, number of visits to amputated predator was higher than to occluded one. Birds risked arriving to ``utter{\crqq} amputated torso while the fear of ``full-featured{\crqq} occluded torso stayed without change when second feeder did not provide safe alternative. Such discrimination between torsos needs ability of amodal completion.

We introduce a novel system for recognition of partially occluded and rotated images. The system is based on a hierarchical network of integrate-and-fire spiking neurons with random synaptic connections and a novel organization process. The network generates integrated output sequences that are used for image classification. The network performed satisfactorily given appropriate topology, i.e. the number of neurons and synaptic connections, which corresponded to the size of input images. Comparison of Synaptic Plasticity Activity Rule (SAPR) and Spike Timing Dependant Plasticity (STDP) rules, used to update connections between the neurons, indicated that the SAPR gave better results and thus was used throughout. Test results showed that the network performed better than Support Vector Machines. We also introduced a stopping criterion based on entropy, which significantly shortened the iterative process while only slightly affecting classification performance.

O arco facial tem seu uso descrito na literatura desde o início do século 20, e atualmente sua eficácia e precisão são controversas. Publicações recentes mostram que a sua reprodutibilidade é passível de erros. Este estudo teve como objetivo comparar a reprodutibilidade do arco facial com a de um novo dispositivo desenvolvido com nível de bolha para a montagem de modelos de gesso em articuladores semi-ajustáveis, por meio da análise de medidas realizadas com a Mesa de Erickson. Os modelos de gesso foram obtidos com moldes de alginato e montados em articulador semi-ajustável marca Bio-art, modelo a7 Plus. A avaliação da reprodutibilidade foi realizada em 10 participantes, com a obtenção de três montagens de seus modelos maxilares, sendo a primeira com o arco facial, a segunda com o dispositivo com nível de bolha estando o participante sentado e a terceira com o dispositivo com nível de bolha estando o participante em pé, cada método foi aferido 3 vezes, por 3 examinadores diferentes. Para cada montagem foram realizadas cinco medidas a saber: a) nas cúspides dos primeiros molares superiores de cada lado (dentes 16 e 26), b) cúspides dos caninos superiores de cada lado (dentes 13 e 23) e c) ponto interincisivo, localizado na linha média. Os valores obtidos foram submetidos ao Cálculo do Erro Técnico da Medida e ao Coeficiente de Variação interexaminador. O presente trabalho concluiu que o arco facial tem uma margem de erro em medidas repetidas maior do que o novo dispositivo desenvolvido. O novo dispositivo mostrou-se mais confortável para os participantes, mas necessita mais testes para avaliarmos sua eficiência. / The face bow has been described in the literature since the early 20th century, and currently its effectiveness and accuracy are controversial. Recent publications show that the reproducibility is error-prone. This study aimed to compare the reproducibility of the face bow with a new device developed with bubble level for the assembly of plaster models in semi-adjustable articulators, through the analysis of measurements performed with Erickson table. The plaster models were obtained with alginate molds and mounted on semi-adjustable articulator brand Bio-art, a7 Plus model. Evaluation of reproducibility was conducted in 10 participants, obtaining three assemblies of their maxillary casts, the first one with the face bow, the second with the bubble level device with the participant being seated and the third level with the device bubble being the participant standing, each method was measured 3 times by 3 different examiners. For each assembly five measurements were performed as follows: a) in the cusps of the upper first molars on each side (teeth 16:26), b) cusps of upper canines on each side (teeth 13:23) and c) interincisal point, located in midline. The values obtained were subjected to measurement of the Technical Error Calculation and inter Coefficient of Variation. This study concluded that the face bow has a margin of error in repeated measurements greater than the newly developed device. The new device was more comfortable for the participants, but it needs more testing to evaluate their efficiency.

This study investigates a phenomenon that I have termed occlusion inhibition. This research and a small number of earlier studies suggest that, in some experimental conditions, when an attended (target) object is partially occluded by a distractor object, there is less attention allocated to the occluded region of the target object than to the visible parts of that object. In the literature, there are mixed results concerning this attentional effect. Some studies find it and others do not. This study investigates the differences between those conflicting studies with the goal of identifying the factor or factors that govern when occlusion inhibition occurs. Evidence is presented to rule out a number of potentially relevant factors such as depth perception, figural complexity, set size, the use of real world vs. abstract geometric objects, the position of occlusion, the number of overlaps in the display, and the adoption of the attend-object paradigm over the spatial cueing paradigm. After all these factors are ruled out, Experiments 3 and 4 provide evidence for a factor that does determine whether occlusion inhibition occurs or not. These two experiments differ only in the fact that participants are required to report the border color of the target object in Experiment 3 and not in Experiment 4. This task was designed to ensure that participants fully attend to the target object. Occlusion inhibition occurs when the target color is reported, but not when no target color report is required. Removing the target reporting task was found to be an effective means of turning occlusion inhibition on and off. The results of these experiments suggest that, if occlusion inhibition is to take place, attentional selection of overlapping figures requires the target object to be fully processed. This conclusion in turn suggests that attention does not automatically exclude the irrelevant portions of occluded objects, but that attention selects the entire location of the object and then, through reiterative feedback mechanisms, fine tunes the information to inhibit areas that do not belong to the object.

O arco facial tem seu uso descrito na literatura desde o início do século 20, e atualmente sua eficácia e precisão são controversas. Publicações recentes mostram que a sua reprodutibilidade é passível de erros. Este estudo teve como objetivo comparar a reprodutibilidade do arco facial com a de um novo dispositivo desenvolvido com nível de bolha para a montagem de modelos de gesso em articuladores semi-ajustáveis, por meio da análise de medidas realizadas com a Mesa de Erickson. Os modelos de gesso foram obtidos com moldes de alginato e montados em articulador semi-ajustável marca Bio-art, modelo a7 Plus. A avaliação da reprodutibilidade foi realizada em 10 participantes, com a obtenção de três montagens de seus modelos maxilares, sendo a primeira com o arco facial, a segunda com o dispositivo com nível de bolha estando o participante sentado e a terceira com o dispositivo com nível de bolha estando o participante em pé, cada método foi aferido 3 vezes, por 3 examinadores diferentes. Para cada montagem foram realizadas cinco medidas a saber: a) nas cúspides dos primeiros molares superiores de cada lado (dentes 16 e 26), b) cúspides dos caninos superiores de cada lado (dentes 13 e 23) e c) ponto interincisivo, localizado na linha média. Os valores obtidos foram submetidos ao Cálculo do Erro Técnico da Medida e ao Coeficiente de Variação interexaminador. O presente trabalho concluiu que o arco facial tem uma margem de erro em medidas repetidas maior do que o novo dispositivo desenvolvido. O novo dispositivo mostrou-se mais confortável para os participantes, mas necessita mais testes para avaliarmos sua eficiência. / The face bow has been described in the literature since the early 20th century, and currently its effectiveness and accuracy are controversial. Recent publications show that the reproducibility is error-prone. This study aimed to compare the reproducibility of the face bow with a new device developed with bubble level for the assembly of plaster models in semi-adjustable articulators, through the analysis of measurements performed with Erickson table. The plaster models were obtained with alginate molds and mounted on semi-adjustable articulator brand Bio-art, a7 Plus model. Evaluation of reproducibility was conducted in 10 participants, obtaining three assemblies of their maxillary casts, the first one with the face bow, the second with the bubble level device with the participant being seated and the third level with the device bubble being the participant standing, each method was measured 3 times by 3 different examiners. For each assembly five measurements were performed as follows: a) in the cusps of the upper first molars on each side (teeth 16:26), b) cusps of upper canines on each side (teeth 13:23) and c) interincisal point, located in midline. The values obtained were subjected to measurement of the Technical Error Calculation and inter Coefficient of Variation. This study concluded that the face bow has a margin of error in repeated measurements greater than the newly developed device. The new device was more comfortable for the participants, but it needs more testing to evaluate their efficiency.

Digital inpainting is the technique of filling in the missing regions of an image or a video using information from surrounding area. This technique has found widespread use in applications such as restoration, error recovery, multimedia editing, and video privacy protection. This dissertation addresses three significant challenges associated with the existing and emerging inpainting algorithms and applications. The three key areas of impact are 1) Structure completion for image inpainting algorithms, 2) Fast and efficient object based video inpainting framework and 3) Perceptual evaluation of large area image inpainting algorithms. One of the main approach of existing image inpainting algorithms in completing the missing information is to follow a two stage process. A structure completion step, to complete the boundaries of regions in the hole area, followed by texture completion process using advanced texture synthesis methods. While the texture synthesis stage is important, it can be argued that structure completion aspect is a vital component in improving the perceptual image inpainting quality. To this end, we introduce a global structure completion algorithm for completion of missing boundaries using symmetry as the key feature. While existing methods for symmetry completion require a-priori information, our method takes a non-parametric approach by utilizing the invariant nature of curvature to complete missing boundaries. Turning our attention from image to video inpainting, we readily observe that existing video inpainting techniques have evolved as an extension of image inpainting techniques. As a result, they suffer from various shortcoming including, among others, inability to handle large missing spatio-temporal regions, significantly slow execution time making it impractical for interactive use and presence of temporal and spatial artifacts. To address these major challenges, we propose a fundamentally different method based on object based framework for improving the performance of video inpainting algorithms. We introduce a modular inpainting scheme in which we first segment the video into constituent objects by using acquired background models followed by inpainting of static background regions and dynamic foreground regions. For static background region inpainting, we use a simple background replacement and occasional image inpainting. To inpaint dynamic moving foreground regions, we introduce a novel sliding-window based dissimilarity measure in a dynamic programming framework. This technique can effectively inpaint large regions of occlusions, inpaint objects that are completely missing for several frames, change in size and pose and has minimal blurring and motion artifacts. Finally we direct our focus on experimental studies related to perceptual quality evaluation of large area image inpainting algorithms. The perceptual quality of large area inpainting technique is inherently a subjective process and yet no previous research has been carried out by taking the subjective nature of the Human Visual System (HVS). We perform subjective experiments using eye-tracking device involving 24 subjects to analyze the effect of inpainting on human gaze. We experimentally show that the presence of inpainting artifacts directly impacts the gaze of an unbiased observer and this in effect has a direct bearing on the subjective rating of the observer. Specifically, we show that the gaze energy in the hole regions of an inpainted image show marked deviations from normal behavior when the inpainting artifacts are readily apparent.

A detailed understanding of cloud microphysical processes is crucial for a large range of scientific disciplines that require knowledge of cloud particles for accurate climate and weather prediction. This thesis focuses on 3 measurement campaigns, encompassing both airborne and ground based measurements of the microphysical structures observed in cold, warm and occluded frontal systems around the United Kingdom, stratocumulus clouds in the Arctic and many different clouds observed over a 6 week period at a high-alpine site in the Swiss Alps. Particular attention was paid to the origin and distribution of both primary and secondary ice and the dominant features associated with ice phase processes. During investigation of cold, warm and occluded frontal systems associated with mid-latitude cyclones around the U.K., secondary ice was often found to dominate the number and mass concentrations of ice particles in all systems. The presence of large liquid droplets was sometimes observed in close proximity to regions of secondary ice production. The existence of these provides a possible mechanism by which rime-splintering is greatly enhanced through the creation of instant rimers as the large drops freeze. In-situ measurements during the cold frontal case were used to calculate rates of diabatic heating during a comparison between bin-resolved and bulk microphysics schemes. Observations in arctic stratocumulus clouds during spring and summer seasons revealed higher ice concentrations in the summer cases when compared to the spring season. This is attributed to secondary ice production actively enhancing ice concentrations in the summer, due to the higher temperature range the clouds spanned. At Jungfraujoch in the Swiss Alps, ground based measurements allowed us to obtain high spatial scale resolution measurements of cloud microphysics and we found transitions between high and low ice mass fractions that took place on differing temporal scales spanning seconds to hours. During the campaign measurements of aerosol properties at an out of cloud site, Schilthorn, were made. When analysing a Saharan Dust Event that took place a possible link between the number of U.V. fluorescent particles and the number of ice particles was found in the temperature range around -10 ºC.

No description available.

Amodal completion enables animals (birds, mammals, but also fish) to perceive partly occluded objects as whole. Most of the studies focusing on the occlusion phenomenon were carried out in a laboratory and were based on either operant conditioning or filial imprinting techniques. This study concentrates on behavior of untrained animals in their natural habitat. Pairwise preferential experiments were used to reveal responses of tits (the great tit, Parus major; the blue tit, Cyanistes caeruleus; the marsh tit, Poecile palustris) to two dummies placed near an experimental and an alternative feeder. The dummies used were the complete dummy of a sparrowhawk and a pigeon, and partly occluded (the lower or upper torso hidden in shrubs) and amputated (only lower or upper torso on the perch) models of sparrowhawks - 15 combinations altogether. The tits considered all variants of torsos to be predators. The great tit and the blue tit perceived the model with occluded lower torso as more dangerous than the one with amputated lower torso. Such discrimination between these torsos requires the ability of amodal completion. The great tit also confirms this ability as it regarded the complete sparrowhawk and the model with occluded lower torso as equally dangerous. In the remaining cases, the number of arrivals...