Ingeniero Civil Industrial / Este trabajo de título tiene por objetivo principal diseñar y desarrollar un módulo de clasificación de páginas web en base a las características de su contenido utilizando técnicas de minería de datos, lo que se traduce en la utilización de contenido HTML, análisis de texto visible de la página web y la incorporación de una variable que refleja la seguridad web según SSL como variables predictivas para la clasificación de páginas web. El trabajo se realiza enmarcado en el proyecto AKORI del Web Intelligence Centre de la Facultad de Ciencias Matemáticas de la Universidad de Chile, el cual pretende desarrollar una plataforma computacional para mejorar el diseño y contenido de sitios web mediante el estudio de variables fisiológicas y la aplicación de minería de datos. La plataforma consiste en la implementación de un modelo que sea capaz de predecir mapas tanto de fijación ocular como de dilatación pupilar de manera rápida y precisa. En esta etapa del proyecto AKORI es necesario mejorar el desempeño de las predicciones descritas, las cuales son realizadas en sitios web reales, de diseño y contenido muy variado. Además el comportamiento que se desea predecir es sobre usuarios de los que se desconoce su motivación para la navegación, lo cual a su vez altera tanto el comportamiento ocular como sus patrones de navegación. Dado lo anterior se propone como hipótesis de investigación: Es posible clasificar páginas web en base a las características de su contenido para solucionar dos problemas fundamentales, por un lado la clasificación agrupa páginas web maximizando la varianza de páginas web entre clases y minimizando la varianza intra clase, lo cual debiese mejorar considerablemente el desempeño del modelo, puesto que predecir dentro de una clase en la cual los ejemplos tienen mayor similitud disminuye el rango de error, disminuyendo, a su vez el error estándar en la predicción. Por otro lado entrega información sobre la motivación del usuario en la web si se conoce el servicio que ofrece la página web, lo que si bien no es información completa para describir el comportamiento del usuario, puede ser una importante variable de apoyo. Para el desarrollo del modelo se utiliza un juego de datos de 138 páginas web, escogidas según tráfico de usuarios Chilenos y luego se implementan cinco algoritmos de minería de datos para clasificar entre siete clases de páginas web. El algoritmo Naive Bayes obtiene el mejor desempeño, logrando un accuracy de 78.67%, lo que permite validar la hipótesis de investigación. Finalmente se concluye que se cumplen todos los resultados esperados y la hipótesis de investigación con resultados satisfactorios considerando la investigación actual.

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One approach to investigating functional attributes of the central complex is to relate its various elaborations to pancrustacean phylogeny, to taxon-specific behavioral repertoires and ecological settings. Here we review morphological similarities between the central complex of stomatopod crustaceans and the central complex of dicondylic insects. We discuss whether their central complexes possess comparable functional properties, despite the phyletic distance separating these taxa, with mantis shrimp (Stomatopoda) belonging to the basal branch of Eumalacostraca. Stomatopods possess the most elaborate visual receptor system in nature and display a fascinating behavioral repertoire, including refined appendicular dexterity such as independently moving eyestalks. They are also unparalleled in their ability to maneuver during both swimming and substrate locomotion. Like other pancrustaceans, stomatopods possess a set of midline neuropils, called the central complex, which in dicondylic insects have been shown to mediate the selection of motor actions for a range of behaviors. As in dicondylic insects, the stomatopod central complex comprises a modular protocerebral bridge (PB) supplying decussating axons to a scalloped fan-shaped body (FB) and its accompanying ellipsoid body (EB), which is linked to a set of paired noduli and other recognized satellite regions. We consider the functional implications of these attributes in the context of stomatopod behaviors, particularly of their eyestalks that can move independently or conjointly depending on the visual scene.

Autism Spectrum Disorder (ASD) is often accompanied by atypical visual attention to faces. Previous studies have identified some predictors of atypical visual attention in ASD but very few have explored the role of conversational context. In this study, the fixation patterns of 19 typically developing (TD) children and 18 children with ASD were assessed during a SKYPED conversation where participants were asked to converse about mundane vs. emotion-laden topics. We hypothesized that 1) children with ASD would visually attend less to the eye region and more to the mouth region of the face compared to TD children and that 2) this effect would be exaggerated in the emotion-laden conversation. With regard to hypothesis 1, we found no difference between groups for either number of fixations or fixation time; however, children with ASD did evidence significantly more off-screen looking time compared to their TD peers. An additional analysis showed that compared to the TD group, the ASD group also had greater average fixation durations when looking at their speaking partner's face (both eyes and mouth) across conversational contexts. In support of hypothesis 2, eye tracking data (corrected for amount of time during conversation) revealed two interaction effects. Compared to the TD group, the ASD group showed 1) a decreased number of fixations to eyes and 2) an increased fixation time to mouths but only in the emotion-laden conversation. We also examined variables that predicted decreased number of eye fixations and increased mouth-looking in ASD in the emotion-laden conversation. Change scores (to be understood as the degree of visual attention shifting from the mundane to the emotion-laden condition) for the ASD group negatively correlated with age, perceptual reasoning skills, verbal ability, general IQ, theory of mind (ToM) competence, executive function (EF) subscales, and positively correlated with autism severity. Cognitive mechanisms at play and implications for theory and clinical practice are considered.

This thesis chronicles the progression toward and creation of my thesis show, Limelight & Indigestion, as well as the cultural, technological and artistic influences and discussions that underpin the works therein. The show is an exploration of celebrity, mass media, and the nature of the desire for fame. I hope to situate my work through an investigation of topics such as Hollywood and the use of green screens and associated technology, our physical and ideological connection to cinema, the absurd in cinema history, and the complex nature of media digestion.

Individuals around the globe engage in sustainable consumption in their everyday life, e.g., when it comes to individual transportation. Although tourism behavior contributes to global carbon emissions to a considerable extent, consumers' awareness of sustainability in the tourism industry is still underresearched. Placing eco-labels next to tourist offers on websites might direct consumer's perception towards more sustainable offers. By employing eye-tracking techniques and surveys, this research aimed at linking information about sustainable tourist offers, perception of eco-labels and subsequent perception and preferences of tourism services. In Study 1, eight existing hotel offers with sustainability certification (four different labels) were selected and their websites presented to 48 participants (four websites each), whose eye movements were tracked. After looking at each website, they rated the overall appearance of the website. Based on the results, in the second study, participants' (n = 642) awareness of labels, their values and attitudes regarding sustainable behavior were found to influence their preference for certified tour operators. In addition, individuals' ideas of their perfect holidays were captured to allow a better understanding of their motivation. This research proposes implementing appropriate sustainable labeling in the tourism industry to increase awareness about sustainability among travelers and subsequently increase sustainable travel behavior.

Master of Science / Department of Psychological Sciences / Lester Loschky / Film is a ubiquitous medium. However, the process by which we comprehend film narratives is not well understood. Reading research has shown a strong connection between eye-movements and comprehension. In four experiments we tested whether the eye-movement and comprehension relationship held for films. This was done by manipulating viewer comprehension by starting participants at different points in a film, and then tracking their eyes. Overall, the manipulation created large differences in comprehension, but only found small difference in eye-movements. In a condition of the final experiment, a task manipulation was designed to prioritize different stimulus features. This task manipulation created large differences in eye-movements when compared to participants freely viewing the clip. These results indicate that with the implicit task of narrative comprehension, top-down comprehension processes have little effect on eye-movements. To allow for strong, volitional top-down control of eye-movements in film, task manipulations need to make features that are important to comprehension irrelevant to the task.

Traditional theories of vision assume that object segregation occurs before access to object memories. Yet, behavioral evidence shows that familiar configuration is a prior for segregation, and electrophysiological experiments demonstrate these memories are accessed rapidly. A behavioral index of the speed of access is lacking, however. Here we asked how quickly behavior is influenced by object memories that are accessed in the course of object segregation. We investigated whether access to object memories on the groundside of a border can slow behavior during a rapid categorization task. Participants viewed two silhouettes that depicted a real-world and a novel object. Their task was to saccade toward the real-world object as quickly as possible. Half of the nontarget novel objects were ambiguous in that a portion of a real-world object was suggested, but not consciously perceived, on the groundside of their borders. The rest of the nontargets were unambiguous. We tested whether saccadic reaction times were perturbed by the real-world objects suggested on the groundside of ambiguous novel silhouettes. In Experiments 1 and 2, saccadic reaction times were slowed when nontargets were ambiguous rather than unambiguous. Experiment 2 set an upper limit of 190 ms on the time required for object memories in grounds to influence behavior. Experiment 3 ruled out factors that could have produced longer latencies other than access to object memories. These results provide the first behavioral index of how quickly memories of objects suggested in grounds can influence behavior, placing the upper limit at 190 ms.

Background: With the rise of streaming services such as cloud gaming, a fast internet speed is required for the overall experience. The average internet connection is not suited for the requirements that cloud gaming require. A high quality and frame rate is important for the experience. A solution to this problem would be to have parts where the user is looking at in a image be displayed in higher quality compared to the rest of the image. Objectives: The objective of this thesis is to create a gaze-based lossy image compression algorithm that reduces quality where the user is not looking. By using different radial functions to determine the quality decrease, the perceptual quality is compared to traditional JPEG compression. The storage difference when using a gaze-based lossy image compression is also compared to the JPEG algorithm. Methods: A gaze-based image compression algorithm, which is based on the JPEG algorithm, is developed with DirectX 12. The algorithm uses Tobii eye tracker to get where the user is gazing at the screen. When the gaze-position is changed the algorithm is run again to compress the image. A user study is conducted to the test the perceived quality of this algorithm compared to traditional lossy JPEG image compression. Two different radial functions are tested with various parameters to determine which one is offering the best perceived quality. The algorithm is also tested along with the radial functions on how much of a storage difference there is when using this algorithm compared to traditional JPEG compression. Results: With 11 participants, the results show the gaze-based algorithm is perceptually the same on images that have few objects who are close together. Images with many objects that are spread throughout the image performed worse on the gaze-based algorithm and was less picked compared traditional JPEG compression. The radial functions that cover much of the screen is more often picked compared to other radial functions that have less area of the screen. The storage difference between the gaze-based algorithm compared to traditional JPEG compression was between 60% to 80% less depending on the image. Conclusions: The thesis concludes that there is substantial storage savings that can be made when using a gaze-based image compression compared to traditional JPEG compression. Images with few objects who are close together are perceptually not distinguishable when using the gaze-based algorithm.